I seem to remeber posting something about Sky Team doing similar to Star Alliance. It only worked if you wanted to include some very particular flights (such as to Urumuqi which can be expensive) or some routes where there are sometimes limited discounts (such as PEK-SZX)

Generally speaking moondog is right. Just buy the relevant tickets individually and make sure you keep an eye on the online fares to get decent discounts

I've been to dozens of Chinese airports and never felt that the toilets were unclean. Almost invariably there is a guy in there on permanent cleaning duties. So long as you're not OCD about hygiene you'll be fine

nickyboy