Make the Spartan Companies have a tab on the friends section of Halo 5 so you can access your members easily.
Implement a voting system or veto system for matchmaking so you do not consistently get stuck with the same map and game mode over and over.
Make it where you can view your team and the opposing team before starting a match to look at their stats / file share / armor / etc.
Have a better explanation of the CSR system in game.
Add Infection to customs at least.
Make it where you can select to spawn with random weapons in a custom game mode.
Do not have instant respawns in SWAT.
Grifball as a future playlist.
Weekend playlists and seasonal events would be great.
Make special armors that require accomplishing hard tasks the requirement to unlock rather than Req packs giving them to you.
I am sure I will have more ideas later but if any of you would like to add on please do.
