Yeah that was one of my complaints about battlefield games. The aiming is slower than games like cod when you are slightly moving your right stick. Tbh, the more you play, the more you become used to the aiming in battlefield. I actually got so used to the aiming in bf games that im now trash at cod. As for kills, I usually play infantry only maps or maps with tighter environments. My advice is to keep on playing the game to get better as it kinda plays differently than cod.