Why not throw off a mound? If you want to continue to become a better pitcher (better accuracy, more velocity) why not throw off a mound? As long as you have the correct mechanics it's not going to destroy your arm.
I wouldn't ice the arm. I mean think of it this way. When your body is going to repair itself, it rushes blood there and it kind of inflames a little bit. That is the body's natural way of healing itself. Icing decreases the blood flow and actually slows down the body's healing time to it's target.