To my horror I realized that, on the Mac, the mouse scroll wheel is useless within FMP. On Windows it proved invaluable in quickly allowing to scroll between hundreds of records/fields/scripts etc. Any solution or hope in the horizon?

It is sad. You are lucky, in a way, that you've only now just run into the problem. The rest of us have been stuck with it so long that we've sort of forgotten that FileMaker ever did have this ability; even though every other single program on the computer does. As I said, sad.