Ali Of The Williams Fight V Frazier Of FOTC?

You are absolutely correct in all of the above.

Ali stayed on the ropes in '71 because he had no other choice, as you point out. He had to conserve energy for later and he knew it.

And the notion that '66 Ali dances, sticks and moves for the entire 15 rounds is laughably naive. Frazier was too relentless and adept at cutting the ring off. He would have forced Ali to fight. And the less strong and weaker punching (by Ali's own statement!) '60s version of Ali would have had much more trouble on the ropes against Frazier than the '71 Ali version did.