Avoid teaching in Shenzhen, there are too many westerners there.

I don't see what that has to do with it? There are plenty of public jobs, and not every "westerner" need work at a TC. And Shenzhen is so big (i lived there for 1 year, and still have friends there) that actually in some areas your chances of seeing westerners are zero to nil.

If you are not teaching in Shenzhen, then where? Guangxi, read what silvb has said about that. No, SZ is not the problem, the corrupt TC's are!