The moderators group is automatic, and people are added/removed by admins via the user admin page. So I think the + Add Users and + Invite buttons should not be shown at the top, and the admin wrench next to each username with options to remove them should not be shown either.
Furthermore, if you try to add or remove a user here it will not work and fails silently, with no error shown.
These buttons are all also shown on the admin and trust level groups as well.