You'd put tape on the front half of the shoe normally... but those that like heel slides and stuff will cover the whole bottom... I wouldn't recommend this yet. As to the posture for the Lindy Hop... think basketball. Lindy Hop is an athletic dance, it doesn't matter if you are dancing at 115 bpm or 315 (and yes we dance this range) you need to be able to change directions in any direction in an instant. Your weight should be on the ball of your foot, your bent knee over the ball of the weight bearing foot and your sternum over the bent knee. Keep the natural bounce that will result and keep the posture... The arms are relaxed the elbows dropped "pointing at the ground".