Sniping takes the most skill because the reticle bouncing is crazy while your getting shot at, and you have to get a head shot. Now I know some will argue that eriene rr4 (or however you spell it, I don't care)can one hit body shot KO somebody, but that is only a 25% chance, which means that you will be aiming for head anyways because there is a 75% chance it does not proc. Also, it has the lowest AA in game which means you still have to have some skill to hit a body shot since there will be little to no help from the game.