1. playable elites in multiplayer or other races
2. Dual Human/Covenant campaign like from halo 2. In halo reach, when i was in the cut-scene for tip of the spear, i actually thought i was going to fight in that big battle, but that didn't happen, neither in halo 4. so in halo 5 there should be an ENORMOUS open battle like that. also i haven't fought a scarab for 3 games, in halo 5 there should be more scarab fights.
3. return of SMG and MAC blast, and the original battle rifle
4. have a forge world where you spawn on a vast land but if you travel high enough you can also go into space, and also spawn elephants, pelicans...just have a significant wide variety of vehicles exclusive to forge world.
5. return of firefight but you start out with a pelican or Drop pod insertion into the map with other A.I Spartans as well. and there should be flood in firefight. and there should be ordnance but instead of weapons it could be extra ally insertions like marines/Spartans/elites. there should also be a firefight game-type where you have to defend your base from enemies, the bases could kinda look the ones like from halo wars except you can go inside the base, and each round you'll be rewarded weapons,ammo and other shenanigans. also 343 should get rid of the firefight customization, to bring back the feel of surprise like from Halo 3: ODST
6. instead of a forge or firefight, replace one of those two(probably firefight) and replace it with an MMO, separate from the campaign, but you use your multiplayer character. if that wouldn't work either, then replace spartan ops with historical missions, or the return of spirit of fire.
7. their should be armor packs included with the DLC's
8. I know this one is a mega long shot but i thought of a new game-type called BATTLE ZONE, where its a 32 v.s 32 live server, where you can drop in and out and you will be awarded credit for whatever you have done, the objectives can change from invasion to capture the flag to territories to assault. the map for this game type need to be grand that can hold up to 64 players and have 1 host for each team, the map should be heavily vehicle oriented with scorpions falcons, pelicans, broadswords, seraphs,banshees,warthogs, mongooses,ghosts,wraiths,elephants, maybe some new vehicles . also heavy ordnance.
9. Fix the UNSC's attitude, get rid of Sarah Palmer, and add a More Noble Character, make the Spartans more Noble and Honorable, i wanna feel like im a hero, like noble 6, or Chief. I feel like a jerk playing as a spartan IV