I can't answer your specific questions, but I can tell you that I usually don't notify an author if I move a quiz within the categories that I edit. On at least 80% of the quizzes I edit, the correct category isn't chosen. Usually people submit to just the root category (for example, Animals) and don't pick a subcategory.
_________________________
Senior Editor and Site Administrator
"I'd rather make one dog happy than please all the dogmatists in the world."
P. Z. Myers