I know different kinds of snakes require different humidity levels but I don't think different individual ball pythons require different humidity levels. All ball pythons need a certain range but some ball pythons are more sensitive to developing problems because of incorrect temperature than others. Maybe it's just the picture but are your ball python's eyes blue? Typically that means they are about to shed unless the morph was born with blue eyes like a blue eyed lucy.
Mites will look like tiny black or red dots typically first noticed around the eye or corners of the mouth and heat pits. If you run your hand along the whole snake's body and look at you hand you might see one or two on your hand if they are on the body of the snake.