Answer:
My teeth are sharp, my back is straight, to cut things up it is my fate.
I am the tool, for inspiring many. Buy me in the store, for not much more than a penny. Don't overuse me, or my usefulness will go.
What has a neck and no head, two arms but no hands?
My love, when I gaze on thy beautiful face. Careering along, yet always in place, the thought has often come into my mind. If I ever shall see thy glorious behind.
What always goes to bed with his shoes on?
Do what he says and you'll be fine, don't and you lose the game.