This may sound silly, but i wish i could set players to team 0 (this is the team in which you are in for example Deathmatch)
I think it doesn't require more comments
Another thing: someone mentioned in another - now locked topic - that you can use /setteamX in all gamemodes, as well as /addbotX in DM, RM and PM, and /addbot in CTF, TM, INF and HTF.