I wouldn't say that Taker "could lose for the first time EVER" at WM 21.
At WM 9, Taker could've reasonably lost to the recently debuted monster in Giant Gonzales. Sure, Gonzales couldn't wrestle, but the feud wasn't going to end there.
At WM 12, if you weren't on the 'net, I think some people thought Diesel could've put Taker down, en route to a title shot against Shawn (which happened anyway).
At WM 14, I believe some people thought Taker was going down to Kane.
At WM 17, a lot of people thought Taker was falling to Triple H, and were shocked by Taker kicking out of the sledgehammer/powerbomb spot.
The rest I agree with. I personally thought Orton had a 0% chance of winning.