So, there is a lot of questionable phrasing and positioning with these tweets. They reference a quote from “Joaquin De Jesus” that I cannot source anywhere. And in general, they are rather ambiguous about who was doing what during the Battle of Manila, which makes it sound like the US and Japanese militaries were equally responsible for the material and human toll of the battle. This is pretty roundly untrue. The Japanese military committed most of the human atrocities. Admittedly, it is hard to discern from the 100,000 estimated casualties, how many were caused by the US military and how many by the Japanese military. However, given the Japanese military’s historical propensity for war crimes (Nanking Massacre, the Bataan Death March only a few years earlier in the Philippines, etc.), scholars widely accept that a majority of those deaths come from mass executions of Philippine civilians by the Japanese military. The following year, Japanese General Tomoyuki Yamashita, commanding general of the occupation of Manila, was tried and executed on charges of war crimes. In his testimony, he revealed details of the massacre, including statements about the Bayview Hotel being used as a mass rape lodge.

Now, even at their most obscured, these tweets do carry a grain of truth. The US military was responsible for a fair amount of material damage to Manila. Originally, General Douglas MacArthur, who was aware of both the close proximity of civilians and civilian centers, had issued a blanket nixing of air and artillery usage. However, that command didn’t last long; the original siege began around the 2nd of February, and by the 10th, artillery from tanks and Howitzer cannons was being used to clear out Japanese positions. Robert Smith, writing for the US Office of Military History, stated that the general perception within command was that continued door-to-door operations would lead to more US military casualties, and while the liberation of Manila was the objective, Gen. MacArthur rather quickly decided that it would be done expediently, if at the expense of caution. US military artillery almost completely razed Intramuros, the old walled-city section of Manila, which was being used as one of the final Japanese hold-out points. The US military also utilized white phosphorus munitions, which are highly flammable and corrosive, and are now illegal; however, at the time, WP was a staple of a chemical weapon arsenal.

So, to try to answer your main question is a bit complex. Generally, historians place the onus of the destruction of Manila on the Japanese military, both for their merciless rape and execution of countless civilians, and also for their usage of historical landmarks like churches, schools, and government centers as centers of operation. Still, this does not negate the fact that the US military used artillery, and that that artillery usage did account for a large amount of property damage, in both military and civilian venues. As for the temperature of the civilian populace after the battle, it’s hard to say. There arent many first-hand accounts with which to validate the claim that Philippine civilians were virulently rejecting the American presence, but then, those accounts also tend not to make the history books.

There are several extensive accounts of the Pacific Theater during WWII that I am referencing here. Foremost, and a great place to start, is with the Office of Military History’s ‘The War in the Pacific’, which offers a robust, if somewhat America-centric account of the conflict in the Philippines. More recently, James Scott penned ‘Rampage: MacArthur, Yamashita, and the Battle of Manila’, which is a fantastic account of the siege and the subsequent massacre by the Japanese. Before that, Richard Connaughton’s ‘The Battle for Manila’ was essentially the definitive omnibus source for information about the battle.

There were atrocities on both sides, not just the Americans. The capture of Manila in February 1945 is described as the fiercest urban combat in the Pacific theater of the war.

The Japanese defense of the Philippines was fragmented, as the Army and Navy frequently did not coordinate. The Navy decided to defend Manilla and managed a simple and fierce defense of the city with minimal coordination. Their intent was to delay Allied forces as long as possible to allow the Japanese home islands time to prepare their defenses; retreat was not seen as an option. Small units were assigned defensive locations throughout the city center, in many government and cultural important buildings. Minefields and defenses were established prior to the battle. The Americans had to fight and clear out each building, finding booby traps in addition to the soldiers. At least 50 tons of mines and shells were removed, to give a sense of the scale.

Initially the Americans were using artillery on confirmed enemy positions, but quickly widened the scale to include enemy observers. Most buildings were subjected to artillery and attack over the month, and civilians hiding in buildings used by the Japanese were killed. What city features the Japanese had not dynamited prior to the Americans arrival, the Americans managed to damage as they took the city.

However, historians have attributed the majority of the civilian massacres and rapes to the Japanese defenders. The defenders morale was low and took out many of their frustrations on the civilian populace during the battle for the city. Many of these are horrific in detail, and is collectively referred to as the Massacre of Manila. The massacre was covered by the postwar tribunals, and several Japanese officers were executed for these war crimes. Scott's recent book studied the war tribunal papers and covers accounts of thousands of civilians burned by the Japanese, raped, bayonetted, grenaded.

While the wikipedia pages (as screened today) for the Battle and Massacre of Manilla are fair summaries, as usual it is recommended that primary and secondary sources be used. I'll note a few below, and welcome additions by others.

"The Battle of Manila". Dr Thomas Huber, US Combat Studies Institute, 2001.

"Rampage: MacArthur, Yamashita, and the Battle of Manila." James M. Scott, Nortan & Company, 2018.

There's a mixture of fact and fiction there, with a hefty injection of revisionism. The battle would be akin to the recent fight to retake Mosul in the sense that a fanatical enemy was deeply entrenched in a civilian area and not only refused to allow the population to flee but actively used them as human shields, then killed and raped them as they were overrun.

Fighting for Manila was brutal and cost the lives of somewhere between 100,000 and 250,000 civilians, mostly Filipinos; there's a memorial to them in Intramuros. As was typical in the Pacific, the Japanese defenders fought nearly to the last man. Initially the Americans didn't deploy artillery or air power to minimize civilian casualties. This resulted in very high American casualties and was dropped when it became apparent that not only were the Japanese using civilians as human shields but were also carrying out massacres and mass rape within the areas they controlled. Brutal urban combat ensued with heavy loss of life and destruction of large areas of the city. The Japanese defenders attempted a breakout, which failed, and then retreated to the ancient walled portion of the city with thousands of civilians to use as hostages. They killed roughly 1,000 of the hostages and the bulk of the remainder died as the Americans took the walled city, which was essentially razed in the process. Mopping up took another month.

Manila, the Pearl of the Orient, was destroyed almost to the level of Stalingrad. Hundreds, if not thousands, of years of Filipino, Spanish, and American history that resulted in a unique melding of cultures from East and West were destroyed. A substantial portion of the cultural heritage of the Philippines was lost.

I'm not aware of any incidents of civilians spitting on American troops who entered the city but I guess it's possible. The Americans were fighting alongside Filipino guerillas, who actually led the columns in, so it's not to say that the entire population felt that way. A recent history of the battle claims there was little animosity on the part of the Filipinos who understood that the Japanese garrison intended to massacre everyone they held, if possible and thus the destruction and loss of life was somewhat inevitable, akin to the fighting in Warsaw, Berlin, or Stalingrad. However, MacArthur also trapped the Japanese garrison in the city which essentially ensured a fight to the last man would occur in a densely populated urban area so perhaps some fault could be assigned there as well. A counterargument to that would be that the Japanese commander ordered the withdrawal of Japanese forces from the city (the Japanese had surrendered Hong Kong and Singapore without urban combat) but some Japanese naval troops disregarded the order because they were under the Navy command. It was these 10,000 marines and about 4,000 army troops that were trapped in the city but they deliberately chose to not leave when they could so "trapped" is kind of a reach.

It's noteworthy, I think, that the Filipinos have a separate term entirely for Japanese atrocities committed during the battle, translating roughly to The Rape of Manila or The Manila Massacre. Japanese troops killed thousands of civilians during lulls in the fighting, massively contributing to the total death toll. They also demolished large portions of the city as they withdrew, setting fires and destroying buildings. They established a rape center at the Bayview Hotel where girls in their early teens were repeatedly raped by Japanese officers. They bayoneted infants in front of their mothers before raping their mothers literally to death. Historically, the vast majority of the civilian death toll has been attributed to the actions of the Japanese. The general commanding Japanese troops in Manila took responsibility for their actions after the war (even though it's debatable whether he actually had control) and was hung as a war criminal.

To summarize, a ton of civilians were killed during the battle to retake Manila and the city was destroyed during the fighting. However, a temporally and geographically concurrent event was occurring, the Rape of Manila, and much of the destruction was caused BY that event (as opposed to DURING the battle). The links shared by OP seem to ignore the concurrent massacre to imply that Americans were deliberately cavalier with the lives of their Filipino allies. I don't think that holds up based on the current historical record.

Part 1

What this person is referring to is the seizure of Manila by American forces in February-March 1945, during which the Japanese garrison went on a rampage against the civilian population. Manila had been spared destruction in 1942 when MacArthur declared it an open city and left it undefended- under General Tomoyuki Yamashita, commander of the Japanese 14th Area Army tasked with the defense of Luzon (the island on which Manila is located), this was supposed to be the case again in 1945. Yamashita testified after the war that “the population of Manila is approximately one million; therefore, it is impossible to feed them. The second reason is that the buildings are very inflammable. The third reason is that because [Manila] is on very flat land it requires tremendous… strength to defend it. For these reasons my policy or plan was to leave Manila outside the combat zone.”1 Yamashita’s overall plan for the defense of Luzon was to withdraw into the mountains and hold out for as long as possible, thereby subjecting American troops to a protracted campaign of attrition in rough terrain. In this scenario Manila factored in only as a supply base, and Yamashita’s orders were to defend the approaches to it long enough to move as much bulk supply out of the city as was possible, where it would go into the mountains. From the outset of the campaign, however, Yamashita had serious difficulty in exerting control over several of his subordinates within Manila due to a dysfunctional chain of command and the personalities of several of the commanders involved. The classic Army-Navy dysfunction reared its head as the commander of the Southwestern Area Fleet, Vice Admiral Denshichi Okochi, reinforced Manila with 4,000 naval troops on his own accord following the Allied seizure of Mindoro in December. This set off a cascade of events that ultimately resulted in Okochi’s subordinate, Rear Admiral Sanji Iwabuchi of the 31st Naval Special Base Force, taking charge of approximately 16,000 men (both naval and army troops) in and around Manila. Iwabuchi answered to Army control by his attachment to Lieutenant General Shizuo Yokoyama’s Shimbu Group, but under the Japanese concept of unity of command this meant little in the long run- Iwabuchi had orders from Okochi to, among other things, destroy Japanese supplies and installations in and around Manila, these and took precedent over any orders that Yokoyama might issue. The list of tasks assigned to Iwabuchi was extensive and ambitious, and this resulted in a clash of staffs in a series of meetings over January 8-13 in which Iwabuchi’s headquarters more or less told Yokoyama that they planned to defend the city. This decision was based on the desire to fully carry out Okochi’s orders, dissatisfaction for the dispositions that Yokoyama had assigned the naval forces in the mountains, and the simple fact that Iwabuchi felt that the city was highly defensible. Yokoyama, unable to do much about this (which in other militaries would have constituted outright insubordination) due to the aforementioned nature of Japanese unity of command, reluctantly placed those army troops still in Manila under Iwabuchi’s command. Therefore as early as the second week of January the fate of Manila was more or less sealed barring a change in Okochi’s orders to Iwabuchi, although in late January Yokoyama issued orders that ambiguously referred to the defense of the city in terms that seemed to convey a desire for Iwabuchi to withdraw upon initial contact.2 This withdrawal was ordered soon after the outbreak of fighting in the city, and emphasized by Yamashita few days later, but by that point Iwabuchi and his men were cut off by American forces encircling the city. For his part Iwabuchi had flip-flopped between defending the city to the death and evacuating his forces, moving his headquarters to Fort McKinley after the battle opened to try and orchestrate a withdrawal before returning to Manila, which he felt was more defensible than Fort McKinley. By the time he received both orders from his nominal commanders it was too late, and he and his forces were trapped inside the city. He informed both that he intended to stay and fight in Manila, and gave this answer both times he was ordered to withdraw in subsequent days.3

No plan for securing Manila existed when American forces reached it on February 3, 1945, largely because intelligence hadn’t indicated it would be strongly defended until the last week of January and because it was hoped that the Japanese would vacate the city. Obviously, this didn’t happen, however, and so XIV Corps improvised. Aware of the need to supply the civilian population with clean water and sanitation the corps took on water supply installations and electrical plants as their initial objectives; once this was completed the corps moved to circle the city. By 12 February both had been completed, though the seizure of the power plant necessitated its destruction. During most of this period American forces operated with limitations on the types and extent of fires that they could call on in terms of artillery support, and air strikes were banned in order to limit destruction of the city and civilian casualties. This changed over the period of 7-10 February, during which the 37th Infantry Division assaulted the Pasig River. During this period the division ran up against stiff resistance in fortified buildings, and began using artillery more and more freely in order to overcome the enemy. The two assault regiments of the 37th Division suffered nearly 800 casualties during this time period, and had come into the action roughly 400 men short as it was due to fighting north of the city over the month of January. These losses were egregious, and so the decision was made to lift restrictions on artillery fires, though the ban on air strikes remained.

Before continuing I feel it is necessary to lay out what’s involved in urban combat and how the opposing sides planned to destroy the other. Urban warfare is, by its nature, incredibly destructive. Streets, alleys, parks, avenues, and main boulevards constitute clear fields of fire that tend to funnel attacking forces- therefore a defender can extract a heavy toll with a handful of men properly armed with machine guns and antitank weapons. Basements, sewers, culverts and any other underground feature that a man can traverse provides the defender with an ambush point, or means of transit, and buildings, whether they be standing or destroyed, can be turned into formidable strongpoints with only a slight bit of preparation. These fortifications require a great deal of firepower to overcome, such as the use of armor or direct-fired artillery, and the nature of the city discourages maneuver- so in order to restore the ability to maneuver demolitions are required in order to destroy walls or obstacles that impede movement. As a result of the simple fact that Iwabuchi planned to fight within the city it was all but certain that it would experience destruction, though the level of that destruction would depend on the tenacity of the fighting. The Japanese fortification of Manila was, frankly, haphazard, likely because the vast majority of Iwabuchi’s command were not trained infantrymen. That being said, however, their efforts to harden the city south of the Pasig were extensive, and turned most large buildings into strongpoints that were fortified inside and out. Pillboxes were constructed inside buildings as well as outside, and physical roadblocks were used to great extent as well, along with minefields, although the latter were poorly camouflaged and not usually covered by fire. The primary indirect fire support that the defenders could count on was mortars, though they also possessed artillery and rockets. Direct fire support came from 20, 25,and 40mm antiaircraft and machine cannons stripped from aircraft and sunken ships in the bay; these were the backbone of the defense in terms of automatic weaponry, as they outnumbered the number of machine guns that the defenders possessed.