As far as MJ being a choreographed dancer....
How many people you do know that have to train the choreographer on how to do certain steps. Not only that, but MJ was known to do a choreographed dance, step away and do his own thing, fall back in place with ease. When you see other dancers dancing beside MJ, you can almost see that they're counting steps in their heads. MJ practiced until he didn't have to think about the steps, comfortable enough to go off and do his thing, then fall back into place perfectly.