I just got back from seeing the movie. I haven't laughed so much in a movie in years, I thought it was absolutely hilarious. I didn't think that Americans came across as being stupid or ignorant as a nation at all. If anything, I was amazed at how hospitable, tolerant and friendly some of these people were in the face of what Borat was doing. Yes, some came across as bigoted, racist, chauvinist or whatever... well, they were just that. Those students were complete idiots with what they said about women and about minorities. Serves them right to be shown in that light, and I'm sure that anyone who sees the movie will agree. I won't repeat what they were saying here, it's too crude and insulting. It was awful and it served them right to be made fun of, IMO.
As for the village in Romania where they did shoot the opening scene. From what I've read, all of these people were very well paid, and in addition Sacha Baron and the crew donated a lot of money to the village + computers and stuff for the school. It was clear that this was satire, and I don't think that any real person there or the real village as a whole was portrayed in a negative way. It was used as a setting for something that is totally fiction. I mean, come on, sorry for the spoiler, but when he shows some mechanic and says the guy is in charge of some machines as well as for doing abortions, it just makes you laugh because it's absurd.
There is the issue of the terrible image of Khazakstan that he is creating there, and totally undeservedly too. It's a relatively modern country really with their own space industry even. But I think everyone knows that by now and realizes it's just used as part of the Satire. I have to say about this point though, that he should have used a fictional country name. If I were a Kazakh I would be upset.
One last point, the crowd here in Israel had bonus jokes. When Borat is supposedly speaking Kazakhstani, he is really speaking Hebrew! That was quite a surprise, and hearing him swear in Hebrew in some scenes was absolutely hilarious.