I agree with some of your points Mic; in particular what you wrote about us lao wai tending to have a dislike for one another, at least on the surface. This isnt unique behaviour to lao wai in China but also in our home countries there tends to be much less eye or verbal contact between strangers. Many people tend to want to mind their own business at any cost and in China theres seems to be this disdain for the other foreigner in the street. Perhaps many of the foreigners here are trying to get away from their fellow
Countrymen/women and hence the distance they keep. Of course it would be ridiculous to write that all or most foreigners are this way inclined but I have seen many who do tend to keep their distance. It would make perfect sense to presume that foreigners are seeking solitude and tend to be the loner type; the great majority are single.

You write that you find Anglo-Saxon women to be bigger than their continental European counterparts! I think that we, generally, only see women from the US, Canada, UK, Australia in China because the market requires native speakers. That would explain your observation but I would add that Southern European women tend to be heavier than Northern women especially soon after marriage; they tend to let themselves go somewhat.