Geez hope i never strike one that stubborn, i would bin it.
I wiggled one off by hand tonight. I think ive only ever threaded and pulled one. Usually a good soaking with WD40 and a couple of screwdrivers sorts them.
Dont hit the end of the crank with a hammer, i bought a tilt a cut that someone had damaged the crank thread on, was quoted $75 for a die nut. In the end the guy down at the mower shop let me bring the machine down and borrow his die nut to chase the thread. Did the nut up rather carefully and its never missed a beat since.
Hope you have better luck with the rest of it.