[Boog]

Something is advancing the timing too far causing the engine to kick back which is hard on starters too. Possibly a pinched or partially broken wire going to the distributor or ecm? Have you had a scanner hooked up to watch live data? Faulty computer or corroded wires there?
I once had a start/no start/shut off while driving issue on a Blazer. For months I fooled with that one. Finally I started grabbing wire harnesses under the hood and moving them around then I found the issue. The wires going into the side of the distributor had been pinched and when I lifted up on the harness it shut the engine off. No start. I pushed them back down and it started again. Ahah. Bad harness and could not see damage from the outside.