One idea is: What if spectators had a chat mode, just like admins, but obviously spectators only. For admins you could put ">" before you chat. Maybe for the spectating chat you could use a "-" or something. This would mainly be useful for when watching duels and such, but not really a big deal.

Second idea: I think I already mentioned this but, have a command for swapping more than one player. Ex: /swap 1-4 6 9.