Re: How to Turn
General advice on turning: hips, foot and knee move at the same time. Knee before foot is just not natural: you're basically forcing your knee to move in a direction it isn't even made for. The more you lift your feet, the less you'll tend to turn your knee before you actually turn your foot.
As for the part of the foot I use for turning, I only turn on the ball of my foot. Turning on my heels delays any forward momentum, whereas turning on the balls of my foot allows me to step in any direction the moment my foot hits the ground.
Isn't stuff like this sport science, by the way?