Currently it's a single checkbox which grants every user permission, I would like to be able to split this into at least two groups.
The first group could be 'user moderation" which would include 'Search for Users' and 'List All Users'. This permission could be granted to moderators and allow them to change avatars / signatures / profile info.
The second group could be 'user administration' which would add usergroup information to the user admin card. It would also include 'Email Users', 'User Permissions' and 'Test Permissions'.
One thing I noticed was the 'Test Permissions' feature allows testing as a super admin, which in my test case allowed my moderator access to a super-admin only forum!