Does anyone know of a way to relax the bow after you pulled back to fire ? (holding down the attack mouse button but did not release the string) I find it a pain as I don't like to lose arrows and there is times that you lose your target and have to fire at the ground in front of you so you can pick the arrow back up again.

If you are on PC press R. Otherwise I can't help you.

Hitting your sheath/unsheath button denocks an arrow.

Awesome thanks a lot !

Nope, I don't.

Both of the above and switching one hand or the other to a different weapon/spell works too.

hit x button.