Aside: all artists should have at least an intuitive understanding of kinematics, mechanics, and optics. If you’re going to represent how something looks, whether at rest or in motion, then you must have some understanding of how it is.
Pixar also learned from the cartoonists that there's a 'folk' physics which is just as important. For example, when a ball bounces, people expect it to deform a lot more than it actually does, so by portraying it that way it's more believable.
Oh, absolutely. Exaggeration, squash & stretch, easing, and other basic principles of animation are necessary to account for how people perceive the real world. It’s just important to understand the difference between perception and reality—to know the rules so that you can break them intelligently.
Yup. Was augmenting, not contradicting your comment.