This is a very conveniently timed question; just a few days ago I received my copy of Christine Haynes' just-released book, Our Friends the Enemies: The Occupation of France After Napoleon, which addresses your every point and from which I have sourced the following answer. If you wish to learn more I recommend you pick up a copy yourself.

After the battle of Waterloo in June 1815, the victorious Allied armies (including those contingents who had not been present at Waterloo) occupied most of France. This included more than 1.2 million soldiers, a truly massive force for the day: 320,000 Austrians, 310,000 Prussians, 128,000 English (and allies), 250,000 Russians, 60,000 Bavarians, and more from smaller states. The occupiers plundered liberally as they went, forcing both public officials and ordinary people to give them money, food and supplies, as well exacting vengeance with no material gain. "We found it absolutely impossible to supply the needs of an enemy army, which was anyway irritated with reason against we who, of our own action, had constrained them to come back a second time to punish us," wrote an anti-Bonapartist farmer. "Thus they fulfilled amply this commission, not limiting the kinds of excesses to which they delivered themselves, pillaging churches, burning villages, devastating countrysides, etc."

The occupying troops were in no hurry to leave, after their swift departure the year prior had been followed by the return of Napoleon and war. George Canning, a British diplomat and future prime minister, wrote: "France is our conquest, and we want to exhaust her so that she will no longer budge for ten years." Looting continued despite attempts to standardize a system of requisitions through the restored government of King Louis XVIII, who was resorted to effectively forcing the richest French families to loan the crown money to pay off the occupation. Between July and November 1815 the occupation was costing France more than 2.5 million francs per day, or a total of nearly 500 million francs. To put that in context, the annual budget Louis had set before the Hundred Days totaled 548 million francs; imagine if the modern United States was forced to pay more than $4 trillion.

(Among the non-monetary looting: an estimated 300 million bottles of wine confiscated from French cellars. This, at least, ended up well for the French: many of the occupiers developed a taste for French wine during their stay, and when they left, they would buy with money what they had once seized with muskets. "They are drinking, they will pay," one shrewd observer in Champagne observed, and André Jardin and André-Jean Tudesq note that the international popularity of sparkling wine took off soon after.)

The British troops, whose occupation zone was the northern tip of France north of the Seine and Oise rivers, were relatively well-behaved during all this. It was the Prussians in particular who were infamous for their violence and theft during the occupation, vengeance for French treatment of Prussia during Napoleonic invasions. Wellington kept a tight lid on his troops based on both personal proclivities and personal experience: "If the system followed by the Prussians and now imitated by the Bavarians is not rejected, the allies will soon find themselves in the same situation as the French were in Spain," Wellington wrote — guerrilla resistance from an irate populace.

Eventually, France signed treaties in November with the Allies which established a formal, limited occupation of merely a stretch of northern France instead of the entire country. This was to be conducted by the 150,000 soldiers you reference: a force composed of 30,000 soldiers each from the major powers and 30,000 combined from the minor powers. That includes 30,000 British soldiers, who were headquartered in Cambrai in northern France. The remainder of the vast 1.2 million-strong occupation force left.

Some of these remaining British soldiers were none too happy with this assignment: a poem from the time read:

Quartered in the mud villages in French Flanders

Where the men caught cold, the horses glanders.

Not everyone objected, though; Russian officers in particular were seen to lament their orders to pack up and head home, abandoning the pleasant land of France (and the pleasant French women).

At Wellington's request, the occupation force was commanded by veterans of the Peninsular War. They were stationed in a series of fortresses along the northern French border, separated from unoccupied France by a demilitarized zone. Its expenses, and those of the rest of the occupation, were paid for by the French government as part of the treaty: a total of 50 million francs per year, plus daily rations for the men and horses totaling another 100 million francs. (Other obligations of the Second Treaty of Paris included the cession of a number of French territories and fortresses and the payment of a cash indemnity on top of the occupation costs.) These rations were still a burden on the populace despite their systematization through the French war ministry, but were less ruinous than the wholesale plundering before the treaty had been.

The daily ration included two pounds of bread, a half pound of meat, some grain or vegetable, some alcohol (either 1/12 liter eau-de-vie, 1/2 liter of wine, or one liter of beer) and 1/30 of a pound of salt (still considerably more than the typical caloric intake of French peasants, especially the meat). This basic ration was customized due to the specific tastes and needs of various troops:

Finding the ration of meat too small for British troops, the Duke of Wellington arranged to have them receive an extra three-eighths of a pound of meat but a half-pound less of bread and no vegetables or salt, with the difference of about one halfpenny per ration to be paid by the British government. Wellington advised that Russian soldiers, who collected less pay than the other contingents, should receive an extra third or fourth of a pound of flour to make their traditional drink of kvass, as well as at least 50 percent more salt and one-thirtieth of a pound of soap per day, which was indispensable but otherwise unaffordable to them.

This was merely for the common soldiers; officers demanded more refined fare, and received it: generals got the equivalent of 12 basic rations per day, majors three, and noncommissioned officers one. This was paid in cash equivalent rather than in kind, as with common soldiers; the officers could spend this money to fill their table with whatever food they desired and could obtain. British officers alone were paid 235,000 francs per month for their meals.

Continued in Part 2