Bones are like locators so 0 0 0 would not be what you want. So you actualy want values for their cordinates. Then just hide the cordinates and use scale and rotate to key them, its pretty much how its intended!
se the bones in maya actualy represent joints not bones a bone is what lies in between the joint so, in most cases the joint would only move if the bone is rotated or in some cases scaled.