Um. Well. I have thousands of ideas, but one a few are actually logically possible.
Tactic Tuesdays: The event coordinators would assign 3 guns you can use in 1 round and would activate some kind of mod on that round (drugged, low grav, etc.). The objective of the game is to eliminate the enemy team without 1 player on your team getting more than 1 kill. (If there are more players on 1 team, then there can be an exception to a player to have 2 or however many people they are outnumbered by.) Also, the Event Coordinators can give certain players "perks" and have that player have a certain amount of time to kill as many players as possible (Whether giving that player noclip for 15 seconds, having his health at 400 for 20 seconds, or some other thing.)
That is one of my event ideas that I think would be pretty entertaining.