[kellyryder]

Well I can help with the first two at least.

First, you can either make a new group or use the Super Moderator group or something. In the group editor, have "Can Access Control Panel" under Administrator Options checked. When you change someone's rank, if you don't see a notice to change the administrator permissions, click the drop-down box and click on the last link saying "Edit Administrator Permissions." If you only want them to be able to have access to changing passwords, set all of the permissions to "no" except "Can Administer Users." Your moderators should be able to access AdminCP and only see the necessary options that way.

For the second problem, the stylevar you want to edit the buttons with is "control_background."