I agree. My biggest complaint was that None of the main characters (excluding Cortana and Johnson) were very well done until Halo 4 (Chief had a real personality and was actually TALKING during gameplay. My biggest hope for Halo Xbox One and the games to follow is that Chief regains his humanity.
“When this is over, promise you’ll find out which one of us is really the machine.” That was Cortana’s final wish for Chief. Despite her good intentions, Halsey took his humanity away from John, and he needs to realize that he’s not invincible and he’s not supposed to be. In weakness we become strong. He can’t win this fight in his own. BE HUMAN!!!
As for gameplay, I agree with alot of the ideas I’ve seen on the forums (Forge AI, going underwater, return Dual Wielding and Firefight etc. However, I like the idea of having Personal Ordinance and armor abilities (INCLUDING JETPACK!!!).
That changed the gameplay dynamic for the better. Going back to the H3 days with no armor abilities and pure arena style gameplay in my opinion, is kinda boring. That said, it would be fun for 343 to brought back the flame grenades, and other pover ups from H3. Also, if youre gonna be notified that your’e near a live grenade PLEASE bring back the grenade explosions from CE! Those were the BEST, EVER!!! Along with some of the old game types like rocketrace(Coming to H4 matchmaking later this year by the way).
Also, there should be more realistic movement when you run or get knocked down (refering to when Chief gets attacked by a knight for the first time) I hope the movement will be more like Crysis 3 cause that was right on the money.
Concerning Spartan Ops: More map variety and gameplay more like campaign. I know 343 wanted SO to replace Firefight but I don’t think its works. SO is great to extend story line but loses the replayability of Classic Firefight. Likewise SO provides the extra story fiction that classic Firefight lacks. The solution: Classical FF with some new twists like fighting the flood, Prometheans, defending a generator, helping with evac, etc. Then continue with SO with less corny dialogue like we had in Ep. 1-5 and more of what they started in Ep. 6-10 better storyline new gameplay (Jackals with A.C. and gravity fluctuations etc.)
Palmer: She needs help (Granted I haven’t played Spartan assualt or read the comics from D.C. so if her character has been fixed there, I apologize 343) She kept complaining about Lasky’s decision to bring Halsey on board Infinity IN FRONT of her constituents!!! Not only that she talks back at him with her infamous “You see a differance?” The fact that Lasky didn’t reprimend her immaturity made him look like a bad leader, and I know he’s not. In future, Palmer needs to calm down and if she’s ever gonna become the female version of Sgt. Johnson she better come up with insults other than eggheads and hingeheads. Please 343! You showed such promise with the story in the campaign, I know you can do the same with SO.
Cutscenes: As a whole, the cutscenes for SO as well as the Prologue and Epilogue were Amazing!!! However, in SO sometimes the actual movement of the characters was too slow, especially during the fighting scenes, as well as when Thorn and Glassman made a run for it from the vest bomb. Also, were are the shields for the Elites and the Knights! I’ve watched the episodes in qestion literly dozens of times but it just doesn’t make sense. Yes, the Knights that Palmer and the Marines engaged were shot at for a while and Palmer did shoot that one Knight at point blank range AFTER hitting it, but I’m still not totally convinced that the knights could be killed that quickly. I might let Lasky’s Shotun his pass since that is pretty powerful, but nonetheless, you never see shields breaking in any of the fight scenes except for that one time when Madsen takes a hit from a Scattershot, draining his shields and somewhat injuring Him. Geater consistancy between cutscenes and gameplay as far as weapons damage is concerned would be a Huge improvement.
Note: I’m not saying they have to be behave exactely how they would in real life (Remember how fast the lasers and needles were flying in Forward unto Dawn? YIKES!!! I have to give the Marines credit for lasting as long as they did. They should get armor that can withstand at least a few plasma hits. And I don’t want instakill like in COD) But at least some greater consistancy would make the whole series feel that much more coherent and cool.
That’s my feedback for 343, and for the record, I think Halo 4 is not only the best Halo to date but also one of the funnest games ever, of all time. No pun intended 
God bless and make every moment count. Can’t wait for 2014.