As far as the knees go that would depend on how you were shooting i.e. with a barricade or free style. Basically what I do is no matter position I am shooting from I am in the most comfortable, sometimes with my knee locked but for the most part they are just unlocked. Leaning forward a little only seems to make a benefit to me when shooting large caliber firearms that produce a large amount of recoil and another time when I lean in the shooting stance is when I shoot fast i.e. steel or I am behind on a string fire and trying to catch up.