Admin improvements for user & site management. PHP

I have an admin area in my small app and need additional basic improvements with a system that has different user levels that are admin (has full control), moderator (can only manage /create/delete users). I need it to have a basic user management page for the admin and the possibility for the admin to add/remove new users and enable/disable features that are done manually as of now. There's already an admin area and almost all the features related to users and othe capabilities are already available as well, but aren't controlled from the admin but manually in a config file. The system can use a mySQL database and passwords in encrypted ripemd160.