@Napoleon: I haven't either, though the ones (now aged or dead) Chinese troops (now aged or dead) fought against were almost all from south korea, and there are numerous ethnic Koreans in the Northeast (an official Chinese nationality). It's an interesting point, though, since foreign Koreans here tend not to associate with many foreigners of other nationalities (except, perhaps, among Korean Christians and (largely) US Christians, but I don't know much about that). I wonder how Dongbei people, including Han, Man and Korean, think of North Koreans, and about ethnic-minority Chinese Koreans - friendly, nasty, or what? And vice versa.

OK, but considered as a single group - which, I'm afraid, is the way all too many local Chinese see them, as locals tend to do in many places - how do you think 'foreigners' rate? I think it's fair to consider tourists separately - and of course there might be subcategory considerations to be made, based on, perhaps, nationality, or geography, or employment, or gender, or whatever.

Yep, all these things happen. I'd add, though, that in cities where there are quite a few foreigners, there are those who accept such relationships without much trouble.

Any opinions on where to find the friendliest - and nastiest - non-Chinese people in China (though obviously 'non-Chinese' and 'foreigner' are pretty broad terms)? I've heard some negative remarks about expats in Shanghai, and Sanlitun in Beijing seems to collect...well, I haven't been there for awhile. There have been a few unpleasant incidents involving foreigners in Kunming, Jinghong and Dali over the years, though for the most part foreigners in these places seem okay, but we've all seen unfriendly remarks, posted by foreigners, about Chinese or about each other here on the forums. What about Lijiang?
Would be particularly interesting to see opinions here from Chinese contributors.
As for friendlieness, I've generally found people in the smaller towns and villages to be more friendly than those in cities. I'm not sure what how this may impact on considerations of people's level of 'civilized'.

I can't answer your question, but I certainly have not found Kunming people to be unhelpful or particularly rude. I found men, in particular, in Sichuan to be, not so much rude or unhelpful, but to make a particularly big deal about foreigners (e.g., a lot of "Look, a laowai!", etc.). I found it annoying, although I got used to it. On the other hand, I found it easier to meet women there, and make friends with them (not just a matter of sexual relations etc.) I lived in Sichuan for 1&1/2 years.
Note that I lived in a city where there were not a lot of foreigners, and so the Kunming syndrome of foreigners speaking English with Chinese and with each other whenever there was more than one foreigner in the group was not a big problem.
I don't find Hong Kong people particularly helpful. Taiwanese, yes, at least if you speak Chinese - lived in each place about 6 years.