I didn't wanna further dilute the excellent guide put together by the guys, it gets hard to find all the info otherwise so just a couple of notes here.
If you want to use the english fix DO NOT add a matrix to your battlenet account. I did and the client loads up fine but the matrix contained on the client is the old style one, not the 3 digit landscape version supported by the battlenet accounts...in other words it goes to 10 not 12 and does not support input of single or triple digit entries. know Bolomas was looking for a fix for this but he said it looks complicated so may have to wait until the next patch.
If you have bound separate old accounts to a new battlenet account, you can still launch 2 clients and have both characters (from separate accounts) online at the same time. At launch after ur email/password it will prompt you as to which of the old the9 account names u wanna start. Simply launch one then start another client and do it again for your other account. Likewise when you recharge you are prompted as to which account u want the tme on.