I agree with much of what you wrote, but Elon is clearly the most important founder of Tesla (and there is a legal settlement with the "real" founders giving him the right to the title "founder"). He was the only person willing to give the original two founders seed funding, hired its most important employee (JB Straubel, the CTO), and Tesla was only able to raise further funding because Elon lead every round. Most importantly, he was always heavily involved. He helped design the Roadster, and when the original CEO came up with a production plan for the Roadster that would have cost $250k/unit Elon fired him and took over, and saved the company by lowering those costs enough to price it at $80k. And then he led development of the Model S, which is really why Tesla became so valuable.
That said, I agree he doesn't deserve any more stock, it's questionable whether he's still critical to their success, and he's heavily distracted with other projects and social media jihads.