In my experience balls respond better to having their upper body skin removed head/neck rather than lower body skin, in terms of lethargy and eating. The only thing I would be worried about on the lower body is the area around the cloaca, just make sure that area is clean and not harboring any build of feces or the sort.
The issue about leaving tail shed is that the shed could cut off circulation if the snake grows too fast. Many snaked have had this occur to them, which eventually lead to dead rotting tails.