Yeah, but at least some things provide nice occasions for fanfic writers to play in the cracks. For example Naruto getting to school younger because no one wanted to keep an eye on him anyway. XD Or the Hyuuga clan promoting cousin/cousin incest. Or things like that. Since there's no word on it in canon... XD

... Others really make no sense. HI KAKASHI'S EYE. yeah, kinda stuck on that. XD;;;