I have one other qualm:
>But baseball players do so by instinctively following simple rules: run in the right general direction, and adjust your speed to keep a constant angle between eye and ball.
Humans definitely do calculate "complex" differential equations to estimate the trajectory of a ball. If not, they literally wouldn't know which direction the ball is traveling in, as you'd only have the position of the ball on the eye's optic plane. Just because processes are subconscious or effortless doesn't mean they aren't happening.