On traditional kung fu, and also on karate the classic punches, but also the other hand techiniches leave from the hip, its called hikite on japanese karate, and when a hand hit the other go on opposite direction, this do the traditional kung fu punch, different by to the boxe punch where the hand are always on Guard near to the face to the protection to the body, now my question is

1 Wy on traditional kung fu the punch are chamberring on the hip, is there a reason ?

2 How can I defend my face, and my body it my hand are on the hip?