Forum registration

Got this Theme yesterday, and absolutely love it. Easy to setup even for someone with limited knowledge. I have 3 questions.

1) How do I make frontend user registration able to use uppercase for their username?

2) The user registration module is waaaay wider than rest of site, and with no BG, making it hard to read. Where to alter this?

3) How to add levels of access to forum sections? (Start as basic, and admin can put in right group).