Let's see:I've added a lot of limitations now, is it balanced okay?
for the prereq 5 ranks aren't enough, you have max ranks at level 5 (because you got 4 at first level)
the table is now readable so that's progress.
Mime: the size limitation is good, help a lot. The one at time limitation is good too.
I still think you need an Hit dice limitation on what sort of creature you can mime. Also we still don't know what kind of control you have on mimed creature.
mimecurse: much better with a will save and number limit.
I think that now it's roughly playable, with far less balance issue.
That said if you want to continue hombrewing I recommand that you look at what is being done on the forum, there's a lot of great homebrewer here. Thing like the gitp prc contest gove great example.
Also it would help if you knew the game really well, it get the feeling that you're missing some of the basic. Good luck.