In my opinion, 343i should definitely look into allowing us to customize each individual weapon in Custom Game options for future Halo games, or for Halo 4 if they can add it by title update or something (unlikely, but one can dream). Imagine being able to customize each weapon individually, from rate of fire to damage to max. ammo. Not only would it add tons more ways of customizing gametypes, but it would also allow 343i to re-balance weapons in matchmaking in a span of a week or so without needing any title updates whatsoever.
Oh and when I say customize weapons, I don’t mean anything like Call of Duty. I mean something like where you could go into Custom Game options, bring up a list of every weapon in multiplayer and alter each weapon individually, sort of like how you can alter base player traits and stuff.
