Footwork and quickness are two things that you either have or you don't. Sure you can make some improvements by getting rid of bad weight and adding good weight but a lot of it is natural ability. Good technique and strength can mask some of those flaws but it depends on the type of player they are lining up against.
I agree, that is pretty much exactly what I said. None of the things BC listed were inherent natural abilities though. Leverage, hand placement, footwork, and technique in general can all be improved.