Number 3.
"A-After about 5 seconds of cranking, there is a different sound, like a whirl, it might be the small pinion disengaging but I'm not sure."
That's not normal. When you crank the the engine, and the engine doesn't fire at all, it should be a continuous cranking sound. With the symptoms you describe, it makes me believe you have a problem with the starter or missing teeth on the flywheel. Think it over and see if that might be your problem. If not, we'll move on to something else.
