My wishlist;
1) Loadouts done away with. Pointless and devalues weapons found on maps.
2) Ordance, done away with. Makes good/lucky players even lucky with special weapons, and cheapens weapons found on maps.
3) Sprinting, done away with. Halo is a modern sci-fy arena/tournament shooter, let it be its own thing.
4) Maps should take heavy inspiration from halo 2 and 3, with some 1 thrown in (for large tdm and other modes).
5) All special weapons (rockets,sniper,grenade launcher(only 1), Brute (thing?) Forerunner laser, some new promethean rail gun, flamethrower, fuel rod and more) should spawn on certain maps consistently. Variety would
6) Moar grenades than the 2 limit, I liked the halo CE 6 per grenade. Also the halo 3 grenade variety was good.
7) 1 manned scorpion with main gun and machine gun all in one. People can still sit on the sides though.
Armor lock (and some armor abilities) in the game as some way.
9) Weaker ghost armor, is ridiculous in Halo 4.
10) Brutes returning, and or the flood, not quite enough enemy variety in H4 coming from H3.
11) Forge that doesn't enforce loading complex/dynamic lighting.
12) Game modes with more personality. For example, if your playing Spartans vs elite invasion (if its in the game) if the Spartans are attacking then it starts with the Spartans on a pelican and some officer telling you your object and dropping your vehicle. If you were elites, then your in a phantom and they're spewing some religious bull****.
13) If there is some space combat or air combat mission, include a battlefront/BF2142 Game mode like Titan where you're trying to destroy the enemy ship.
14) No unlocks, let people customize how they want to look or lock them behind achievements, so people have to earn em.
15) 1-50 matchmaking level, your skill level determines which your emblem (or emblems you can choose from). You're naturally matchmade with people around your people in order to keep an even playing field.
16) Battle rifle that doesn't have orange on it, and is a 4 burst kill like Halo 2.
17) DUAL WIELDING, with smg's focused on duel wielding. Hell, it might even be a good idea to deal wield 1 weapon like a rocket launcher along with a small weapon. Idk probably unbalanced.
18) Time to expand the universe, either make the story more interesting with it being more personal (like the UNSC and Covenant hunting MC, but working together to do so and are living together?) or add new races to throw into the mix, without brutes and flood and older characters (Miranda,Sgt Johnson, guilty spark, cortana) and just the forerunner + elites then the game will just feel like a lazy attempt to keep the series going.
19) Mission variety that blows Destiny away, too many "Go 3 terminals and press button".
20) Flag carrier in CTF runs the same speed as normal players, stop trying to appease casuals by making them run faster.
21) Very expensive (or not) but high quality servers to ensure the best competitive environment. Halo is big enough now to continue growing without the CoD method of making newbs feel badass in a ridiculously one sided match that hooks as if they just got high for the first time. I'd argue that those who care enough to want to compete are even more hooked, and should be focused on instead of universally reducing gameplay quality to compensate for talent, or lack there of.
22) Humanity the underdogs again or at least balanced, in halo 4 they were dominating the universe (supposedly)
23) Aim assist on competitive playlists (ones that aren't casual, that effect your rank) disabled by default.
24) A protagonist other than Master Chief, I like that they are eluding too (pretty much confirming) a female spartan and other characters working with her. Also, the covenant campaign in Halo 2 was interesting, you got to play from a different perspective with different weapons shoved down your throat.