I think it's important to note that the New Historians are not a monolithic group. It would be far simpler if they were, but unfortunately, they are not. They span a group that goes from Simha Flapan to Benny Morris to Ilan Pappe, in title, and each has very different opinions on very different arguments.

The New Historians were, as you note, a reaction. They were a reaction to the traditional view of Israeli history, utilizing primarily newly released archival documents, to try and revise history. Some argue that they fell into second-option bias, and overcorrected, at least some of them, while others believe they did not correct far enough. It's hard to say; so much remains unknown, hidden, or not shared in Arab and Israeli archives, that it's hard to be certain. It may be decades more before we have the fullest picture, if we ever get it.

Now I'll try and condense my response to each specific part:

And they make claims like these also according to wiki: The official version said that Britain tried to prevent the establishment of a Jewish state; the New Historians claimed that it tried to prevent the establishment of a Palestinian state

The British did not have a single policy that lasted the entire time. Nor were they always monolithic themselves in their policies. The British in the early stages, say the 1920s, are widely believed to have been supportive of a Jewish state. But as time went on, including to the 1940s, the British were far less supportive of this. Indeed, some parts of British intelligence were ardently trying to prevent a Jewish state from coming into being. In the past decade, this has become increasingly clear; there are both Israeli intelligence and British interview transcript histories, and both indicate that the British were not altogether supportive of either state being established; instead they were trying, some argue, to have the Arab states divide up the territory themselves.

French archives seem to confirm this as well. Syrian documents seized by the French reveal that there were contacts between the Arab states and British intelligence. The official policy of diplomacy took a more ambivalent tack; abstaining on UN votes for partition, refusing to take positions clearly and publicly, and the like. The covert policy was different, informal, secret, and may have even deceived the British government by providing selective assessments of the region, resulting in the British intelligence services deviating from official British policies.

So in a sense, the official government policy went from largely supportive of the establishment of Israel, to largely negative, to largely ambivalent, but altogether there was an undercurrent of British activity picked up by the Zionist leadership that some British forces (officially or not) were trying to prevent the creation of either a Jewish state or a Palestinian Arab one.

The official version said that the Palestinians fled their homes of their own free will; the New Historians said that the refugees were chased out or expelled

As in all things, it is complex. The official version did indeed stress flight, and severely under-stress expulsion. At the same time, the New Historians differ as to how much expulsion took place, and whether there was a central "policy" of expulsion. Benny Morris, for example, does not believe there was a central "policy" to expel Palestinians, merely decisions made in the field by commanders who were not told "don't do this". Others, like Ilan Pappe, try to cobble together pieces of Israeli policy to argue that expulsion was a policy. It seems more likely to me at least that there was no policy centrally, but that Israeli leaders were aware and at least tepidly supportive of expulsion in principle, but also did not enforce any such policy or ask commanders to do so generally.

While it is clear that expulsions occurred (on both sides, mind you, of that war), and that the official version was incorrect, the question of how much is also still unclear and always will be. Morris's painstaking reproduction of the "four waves" of Palestinian refugee flight seems to suggest that around 25-33% of Palestinian refugees were expelled, and this is of course a complex subject, so I'll leave it at that.

The official version said that the balance of power was in favour of the Arabs; the New Historians said that Israel had the advantage both in manpower and in arms

It's quite accurate to say that in manpower, Israel had an advantage. This isn't because Israel had more people; far from it. Israel simply mobilized more troops, while the Arab states refused to divert sufficient troops or mobilize enough troops to combat them. Israel put 13% of its population in uniform, a number that would be unthinkable in most modern states today; this proportion was roughly in line (and perhaps slightly higher) than the number of Americans who served in WWII. This vast, wide-ranging mobilization allowed the Israelis to have more manpower. Of course, this is not necessarily sustainable, as anyone will tell you; each soldier fighting or working for the military is not producing agricultural goods, economic output generally, and a drain to some extent on the public fisc. Thus Israel was still at a disadvantage, in the sense that keeping 13% of the population in uniform permanently or long-term would be difficult. On paper, the Arab states had at least 50% more troops than Israel, and the Israelis believed that they did in fact have these troops, but the Arab armies were smaller in reality than on paper and not all deployed to fight Israel.

As for the advantage in weaponry, that was undoubtedly with the Arab side at the start of the war. Unlike the Arab armies, the Israeli army had almost no heavy weapons at the start of the war, and was able to produce light arms but needed many more (as well as ammunition). Also unlike the Arab armies, the Israelis had virtually no planes, though they would get a handful soon through smuggling them in. I think it's safer to say that the Arab states had a weaponry advantage, and local advantage in manpower at the start, but the Israelis mobilized far more in manpower far more quickly, and the weaponry was equalized over the course of the war as Israelis captured and smuggled in (or in rare cases, signed arms deals as with Czechoslovakia) weapons they lacked.

The official version said that the Arabs had a coordinated plan to destroy Israel; the New Historians said that the Arabs were divided

Well, the reality is that both are true, though I'm not sure this is a division between official versions and New Historian versions. The Arab states did put together a plan of attack. They simply did not follow it at all, because they had different goals and were divided. But to Israelis at the time, they expected a coordinated plan, and may even have known one was being formulated.

The official version said that Arab intransigence prevented peace; the New Historians said that Israel is primarily to blame for the "dead end".

Here is perhaps one of the biggest controversies. Some New Historians do, indeed, blame Israel for the lack of peace. Others do not, and blame Palestinians. Some have even blamed Israel and then switched to blaming the Palestinians, or vice-versa. There is no way to be entirely correct on this question, but suffice to say the answers are never entirely one way or the other, and you should view where they put the majority of blame, not entirety of it, in analyzing this point.