A grenade killing you or not largely depends on the amount of health a person has. But anyway, here's what I think they need to patch:
1. Remove bloom and slow down the ROF for the DMR to compensate.
2. Weaken armor abilities. Make them last significantly less than they do or make them take far longer to recharge (the better option). Also, remove jetpack an sprint from v3 (not a patch, but still.
3. Weaken grenades by increasing length of fuse or decreasing blast radius.
4. Reduce rocket damage (there's no way I should be able to shoot the piece of cover that someone is standing behind and kill them)
5. Back to the Halo 3 beatdown system (new one renders shooting useless against an opponent rushing you for the beatdown trade)
6. Ranking system for some competitive playlists, either back to Halo 3/Halo 2's 1-50 system or something new. Must be based on wins and losses and gives people something to work for. If noobs don't like it, they can play Arena or something unranked.
7. Fix inconsistent nade bouncing issues (Frag's get stuck on the floor randomly).
8. Fix host changing issues.
9. Spawn system needs tweaking. Its far too easy to spawn beside enemies or in a combat zone because a teammate is there, I don't know how many times I spawn into nades, a sniper scope, or beside an enemy (one time in Snipers on Cage, I spawned between drop down and snipe spawn with an enemy at snipe spawn and two at big tower)
10. Find a way to make individual skill more of a factor. Reach is far more teamwork based than H3 and its almost to the point where no one does anything without a teammate and it turns into a standoff because no ones willing to leave cover and do something because they know they'll die
8.