More ranked playlists. I wanna see a 2v2 slayer playlist and a FFA playlist added as soon as possible. Would also like to see a 4v4 slayer only playlist (taken out of the OBJ playlist), a possible 1v1 playlist, and the new Attrition mode if it plays well.
In ranked you should only be spawning with one grenade. And all grenade pickups should give one grenade. This will promote more scavenging (which is always a good thing) and indirectly solves the grenade spamming issue without actually changing it at all, as grenade spamming is a part of Halos identity. Its just a bit too oppressive right now, with this change you would have to think about when to do it a lot more.
Social needs the option to choose which modes you want to search for. It also needs more modes like FFA, King of the Hill, Infection, SWAT, Fiesta, etc.
More XP should be given based on performance and medals earned.