Im no expert but i beleive that if ur shifting down u can jump from 5th to 3rd as long as u rev match(<---my preference) as far as shifting up and skipping from like 3rd to 5th i really dont see the point.
YES, downshifting and skipping a gear is bad
YES, upshifting and skipping a gear is bad
YES, BOTH upshifting and downshifting and skipping a gear is bad
NO, it does not harm your transmission in any way as long as you don't jam it into gear
Im no expert but i beleive that if ur shifting down u can jump from 5th to 3rd as long as u rev match(<---my preference) as far as shifting up and skipping from like 3rd to 5th i really dont see the point.