Long post but i made it
1. Yes its true you cannot transfer toons between us / eu / ch.
2. All addons you can use for US (download from curse) can also be used in China. You can use the same client (modified) as the one you use in US.
3. At the moment there is a big move going on in Area 1 (guangdong and Shanghai) this is the most active area of now and you are sure willing to come and try your connection.
If it is to laggy there are few things you can use to improve your connection such as a vpn like 27net the costs would be:
27rmb 1 month
48rmb 2 months
66rmb 3 months
99rmb 5 months
or the Leatrix plug in (free):
4. Recruit a friend is active in China and I happen to want to start lvling a new toon as soon as cata comes out also because the first part lvl 1-60 is completely revised and the exta xp wont do any bad so im up for that
5. Glory to the HORDE !!!