You could always try defense levels in between before you go straight to being a zerker, I have made many different kinds of pures over the years and 10 defense pures have grown to be my favorite, no need to rush something you could later regret.
Rush people and ko them before they have a chance to react, I don't really know when people turned the wilderness in to some safety zone where it's proper to ask someone for a fight or you're a "newb". The way I see it, be ready at all times, and kill them before they kill you. You could do a nice knives/d claw combo for fast KOs