Equipment should be fine, but you'll lose any points assigned to the vanilla Masteries. I used to use this to give myself back the right number of skill points:

http://tq.soulseekkor.com/

No idea if it works on TQ:AE.

Old characters can be ported across just fine if they are already Path characters.

Oh, also, that soulseekkor thing works fine for TQ:AE