1: Armour Abilites give a bit of variety to Halo 4, they aren't totally needed to play the game, and you can easily go well without them. Lack of an argument by you however makes that point pretty much invalid.
2: The DMR is about the only OP loadout weapon. Just needing a slight RoF Decrease and it'll be fixed totally. The other weapons can however easily take out DMR users, since I've done it, I know it can happen.
3: Dual Weilding was hardly an essential part of Halo. Only being in 2 games, it didnt serve much of a role and could be way over powered (Plasma Pistol and Magnum combo). Glad they remove this over powering feature, it wasnt needed at all.
4: I have to argue Exile is one of if not the most colourful map there is on the Entire Franchise. Lush green to the bright brown cliffs, easily colourful. Some maps like complex or Ragnarok could seem at first glance to be dry and "bleached out". But when looking at the finer details it is bright in its own sense, and doesn't resemble CoD or any other game at all.
5: Sprint was needed since Halo CE. Having a super soldier not being able to run was absolutely redicilous. Since the books heavily implied the ran a lot, why did it take 5 games to finally put it in. Sprint has been one of the best inclusions to any Halo game I can think of.
6: I am disappointed with 343 Industries also. I also wanted to play large scale CTF games or even BTB Heavies. But seems we are stuck with BTIS for some time, good to know that 343 Industries confirmed they have plans for BTB though, so the future looks promising.
7: I think this was a good addition. Power Weapon campers ruined the flow and balance of a game. I remember staying high up on the rails in Boneyard (Halo Reach) near the sniper spawn, easily gaining kills with a huge amount of ammo. While I was getting 20+ kills with it alone. I knew I wasn't doing the right thing by staying there. With the Ordnance Drops, it allows a more fair weapon play. Able to get weapons you want, without dying 5 times for it. With that being said, you hardly last long with a ordnance I've found, so it's balanced.