Always put steady aim on your classes aswell, looking at your play style and the fact that you seem to have trouble pulling left trigger before the right one this would help. Other than that just keep practicing on your skills, work out what suits you best. I also noticed you have extreme conditioning as your 3rd perk on the M16 class. This is the most pointless perk 3 on team deathmatch in my opinion, as you need to be taking yourself out of sprint mode as you go round a corner.

Dont throw a grenade at yourself every time you camp in a building... and try to use a silencer if you are going to camp. Your death by the nade at 1:15 was because you camped without a silencer and he saw your dot on the UAV

on the P90 you need to tap it no hold because if you hold it the acc. is bad and there is to much kick in it....

also, you need to check youre corners when you run through a building or tight space, cause there might be someone there if you check your corners you most likely will kill him before he can kill you,if someones there

im no beast at deathmatch, but when you turn a corner and theres a guy in your face just stab them, make it second nature to do so, you save some ammo and you dont lose momentumbut thats just my opinion, what you did worked