I think Rumble Pit should stay as a permanent Social Playlist.
I think people should be allowed to play it as a fireteam as teaming doesnt happen that often and its social so it wouldnt really matter anyway.
The modes I would like to see in it are:
Snipers (S7s Only)
Escalation Slayer (Gun Game)
One in the Chamber (Tactical Slayer Settings. Spawn/Respawn with one bullet. Every kill generates a bullet.)
Sharpshooter (All players start with the same randomly selected weapon. Then after 30 seconds everyone gets the same new randomly selected weapon).