You don't have to remove cool things you think would be awesome in matchmaking.
All you have to do is make them available in Custom games, that way they will still be in the game and usable at players want for fun.
-Duel Wielding
[Double energy swords, smgs, made up weapons]
-Almost anything you were gonna toss out of the final game for matchmaking.
All of those fun aspects can be used in custom games if they aren't going to be used in Match Making.
[Hech, even toss in the brute shot or grenade launcher back.]