Might it be possible to have a few extra pieces of information in the user admin panel, and be able to sort by them?
1. I'd like to see an online indicator. Ideally a simple light, rather than words (online/offline). It would be handy to make a quick check on the number of online users, irrespective of rank.
2. Would it be possible to record and display the last time a user logged in? I can imagine this might be more difficult, depending on the existing logic....but it would be really handy to be able to check when a user was last active, contact them to check if they are still intending to be active, and delete them if not.