The puller threads into the rotor and gets tightened up against the end of the crank; if the rotor won't come off after tightening as much as you can, then you TAP on the puller to pop it loose. A hardware store bolt may work, but be aware that the end is not relieved and most likely not square, and may dig into the end of the crank.
I don't understand how bending the end of the crank could gouge the cylinders?? If the crank is indeed bent, the case is probably damaged as well, and it may be easier and cheaper to just buy a whole motor.