AAHHH WP Memebership Plugin Problems!

If you use something like aMember I think they will install it for you:
http://www.amember.com/

I think it will be easier to have plugins on each of the sites. Your English and Chinese Members would be separated though.

You might need to look for a custom solution to this.

Good Luck

Well you are looking for a customized plugin. Look at this community thread btw:
http://wordpress.org/support/topic/plugin-wp-members-how-to-translate-to-other-languages