I'd prefer it if knifes were completely removed, or at least replaced with maybe hitting the enemy with the barrel of your gun, not doing much damage but making their hipfire inaccurate for 3 seconds or so. I'd rather have a clusterfuck of hipfire when I'm in melee range of an enemy than whoever knifes first. I hardly use the knife, I don't wanna be one of those people that rely on it whenever someone comes that close. I've noticed a lot of the time when people use it they just swipe the air, or lunge at me and completely miss. Fuck relying on that.
I like Unreal Tournament's melee, it's a melee weapon that has to be equipped, but also charged to 100% to score an insta kill, plus it doesn't automatically go off unless you (yes, you, not the computer aided by aim assist) direct it to their body at point blank range. It's more of a humiliation kill, which is what they should be. Plus, it isn't entirely useless because it can be used as a secondary to shield fall damage, bullet damage, and allow you to jump higher (at the cost of health).
As for grenades, I don't like them. On FPS's now I've noticed people immediately throw them whenever the enemy runs out of their line of sight. I know they can be dodged, but I'd like it if frag grenades were rare, and maybe stun/smoke/flashbangs were given to you when you spawn, not fucking frag grenades and two of the other type.