Dunno why I made such an effort considering I really doubt its too late for them to affect the patch, but fingers crossed:
1 Melee System. I did prefer how this worked in older games, the lack of bleed through is jarring and leads to a lot of double melees, as even if someone puts 3 shots into an opponent, the opponent can simply run up to them and bring themselves on an even playing footing without risking deaths which is what would have happened in older games if a significantly weaker opponent attempted the same move.
2 Nade placement. Perhaps I havent adjusted to this properly, but compared to say Halo 3 where nades were used pretty tactically to strip shields and had to be placed very much under a players feet to do so the Reach nades feel very random and placement still seems off.
3 Player movement/ Inertia system. Im just personally not a fan of the sense of weight that these Spartans have, a lot of the movement feels stiff and I feel as though this has impacted on gameplay. Strafing doesnt exactly seem common anymore.
4 Individual Weapon power level adjustments - currently if the damage is set to a value which allows for the DMR to be a 4 shot kill the Sniper and nades become super powerful, which for me is partly the reason I dont enjoy Classic as much as I would have hoped, letting each weapon be adjusted on a individual basis would get past that problem, whilst allowing for some interesting tweaking.
5 Bloom, if it cant be totally removed hopefully it can be toned down to levels where its not noticeable. If this was possible I guess technically a rate of fire would also have to be patched in for all the different guns. That would be pretty sweet.
Noticeable mentions the Sniper aim assist is very high at the moment which leads to very deadly and less satisfying to use weapon.
Player models can sometimes be quite hard to spot; I may be off the mark but I have seen this referenced on another forum: perhaps draw distance is to blame on larger maps like Haemorrhage? Do Spartans render properly at distance?
P.S. I loved Jessicas Armour lock suggestion.