Answer:
Double my number, I'm less than a score. Half of my number is less than four. Add one to my double when bakers are near. Days of the week are still greater, I fear.
I cannot be felt, seen or touched. Yet I can be found in everybody. My existence is always in debate. Yet I have my own style of music.
Crooked as a rainbow, and slick as a plate, Ten thousand horses can't pull it straight.
What can be swallowed, But can also swallow you?
Only one color, but not one size. Stuck at the bottom, yet easily flies. Present in sun, but not in rain. Doing no harm, and feeling no pain.
You use it between your head and your toes, the more it works the thinner it grows.