My primary concern with using the start/stop button was exactly stopping - i.e. considering the engine did not start, would pressing the button again stop the starter or not? It seems you think it would, and that is my hope also. Exactly how long should I let it crank was the second question... I'm guessing like 2-3 seconds is enough? Or no?
I must say I didn't realize that accessing the crank required disassembly, but in all honesty I haven't read about it all that thoroughly. Have you seen any DIYs for either method 2 or 3?