So having a single list of playlists seems a bit redundant to say the least especially when you have to scroll to see a playlist, that's not very good in terms of HCI, as you should always be able to see the playlists at first glance. 
  
In my mind the way Halo 3/Reach separated the playlists into groupings makes the lists much more manageable and dynamic. Below are suggestions to playlist groupings with suggested defaults and maps for use. 
  
CSR Playlist 
FFA Standard - Mainly slayer with lower chance of objective types. 
Team Slayer - Basic team slayer 
Team Snipers - Team snipers 
Team SWAT - Team SWAT (1 loadout only?) 
MLG - TBA see my suggestions for playlists as a whole below. (Small maps + community maps) 
Doubles - See below as well 
  
All CSR playlists should playout as classic Halo games (same loadout at start, weapons on map, no abilities? no ordinance, reach kill limit not score) 
  
Unranked 
  
Slayer playlists 
Infinity slayer 
Big team infinity slayer 
Multiteam 
Unranked FFA (rumble pit) 
  
Objective playlists 
CTF 
Oddball 
Big team objective 
Skirmish 
  
Community 
Griffball 
Action sack 
Flood 
  
If you want to add any suggestions or questions please leave a response below.