I don't know how much control you have over the Tab menu, but IF it were possible, I have two modification suggestions for the menu:
1) Player's rank appears (color the names)
2) Display who is AFK (something like "player1 <AFK>")
3) Some kind of highlight on the map owner

Just some things that would make it easier to tell who's actively online.

Consider your walls humus'd.

Unfortunatly the playerlist (holding the TAB key) is controlled by the client, not the server. Information like that can be changed, but it would only appear if you have the modified client, so it's not very practical.

Ahh well, it was worth a try.