Yes, yes, and yes. You are seriously under-estimating the natural athletic talent of all of these men.
They would be slower, weaker, and have worse shooting form than they do today.
They would be faster, stronger, and have better form than they did back then.
Yes, he did. There were limits on how you could play zone back then (such as having to be in area X when your nominal person was in area Y and the ball was on the perimeter), but coaches found ways around them.
You're kidding, right?
Mark Eaton , perhaps not, because (IIRC) he was a low-post-defense specialist, and the game has moved away from that with the new rule changes. Mutumbo would have been fine.