Answer:
Gets rid of bad ones, short and tall. Tightens when used, one size fits all.
What turns everything around but does not move?
Looks like water, but it's heat. Sits on sand, lays on concrete. A play on the eyes, but it's all lies.
It's equally comfortable in an orchestra and a geometry textbook. What is it?
Used left or right, I get to travel over cobblestone or gravel. Used up, I vie for sweet success, used down, I cause men great duress.
What is always coming but never arrives?