Your squats look pretty good to me. You could potentially lean over a little more. This would keep your knees from coming as far forward as they are and help you to drive up with your hips, but there is nothing terrible happening in any of these. You have a hint of shift off to one side on the front view. Why not try a 1/4 piece of rubber or wood under your shorter leg?
What is a racking problem in the squat? How much pain are we talking about in your knee?