Allow me to point out a small flaw in your theory.
Where do they Chinese get the money to buy up houses in California? From us. Their economy is heavily reliant on export of cheaply manufactured consumer goods. When we go down, so will they. If American and Europe collapse, who's going to buy all the stuff that they make?
Right it CAME from you, its already here everywhere, its sitting in people's bank accounts. There are more middle class/rich people in China then there are PEOPLE in the USA. Prices are getting stupid now, my job which 15 years ago in Beijing paid 800 dollars a month now pays out 5000/month. The economy here is in the midst of switching to IMPORT. You can't find a house in this city for under $300,000 dollars and the population here in just this city alone is 30 million.
My wife who was born into abject poverty along with her brother and his wife all make in upwards of $1000/month each (in the north). In a city where it only costs about 200 bucks a month for a bachelor pad and food, the Chinese are banking some serious money each month.
Nobody is going hungry in China. When the government repossess a house its cause for celebration because they pay out current market value to the owners or give you a brand new place.
Listen, culturally, things here suck but economically these people know how to do business. They aren't completely dependent on the USA if thats what you think. All of the surrounding countries buy from China, infact every country in the world imports cheap chinese products and if you haven't noticed there are Chinese in almost every city. Even if the US folds, China can self sustain and they'll be descending on American banks to buy up foreclosures like you've never seen.
The upper middle class here own 3 to 5 apartments on average. There won't be a collapse or a war, its just going to be money changing hands and ghettos setup to house the american workers too stupid to join the yellow families. I don't know if you've bothered to look around lately but California and Florida are starting to be bought up by the new 'snow birds'.
Listen man, the idea is that everything you buy in a Walmart comes right back to China, they produce it, they collect the money on it. There is nothing you can do to stop it. The money is already here is just changed hands and it will likely change hands back to Americans in smaller amounts when they buy up the real-estate but the fact is that the Chinese will OWN the land. The majority of Americans who don't own anything will be working for Chinese owned companies, living in Chinese owned houses, paying Chinese landlords. .
If you don't buy it, go look at what happened to Vancouver. Americans made the Chinese what they are today.
More importantly, CHINA put a robot on the moon, this past week. That's the kind of money floating around here now.