Question 2. No, clearly not. Question 1. No, but... he was still riding high on an 87 fight winning streak. It was kind of like when Arguello fought Pryor, he was a dominant champion moving up. He might have slipped from his very, very best but no-one was saying much before the fight about Chavez being too old or past his prime. He was held in very high esteem, was still considered the no. 1 fighter in the sport at any weight class and he was facing someone who himself was not a natural welterweight so the move up in weight wasn't considered a huge factor.
No and no, but neither of them were. Whitaker was closer to his best, but it wasn’t until just after that schooling that Chavez began to drop off in a big way. Some would argue his peak, or true prime, or whatever the hell guys are gonna call it, was 5-6 years earlier at Lightweight. I don’t think any of them would argue his general prime, or time spent at the top, was short lived. We saw some of his very best at every weight he was a champion. Even if he was starting to pass it by the Whitaker fight, that past prime version was still clearly a top 10 pound for pound fighter. Just not for long after that.