I realized that the original was taken down, so here I am explaining this aigan a couple of months later.
So lets get to it, I guess.
Part 1: Weapon Stats
Each weapon has its stats, and the damage is the most important thing about it. Buuut, mostly you guys care for how much "pew pew" deals. But the body damage kinda matters too. It's OP to aim at the head with a sniper, because pretty much all the snipers have the same head damage to litteraly put your opponet back in spawn. But have I ever told you you can also do that with any other weapon at any part of the body? Yeah well thats what body damage is. If you look at how much damage the weapon deals at the legs, arms, torso, and head, you can aim at one of those parts and deal as much damage as a sniper headshot would do if your guns damage base stats are the right ammount. But stock grenades won't 1 hit if its not close enough to your opponet that the explosion radius only hits half of your body. (for example your arms and legs) So if you DO want that to obliterate your opponets you can litteraly ATTACH it to the enemy body and the radius will hit all of the body parts, and count those up to probably get 100.
Part 2: Keybindings
Finally I get to do this. Soo first of all you want to set your- wait I can just post a image and be lazy about it. Well I have no choice. 
Well there you have it then Cya I guess.