As far as I know Float materia/magic (depending on the game you play) only slightly raised you above the ground and allowed you to walk on air.
I didn't really see any evidence on Float allowing you fly or perform kilometer high jumps.
As I've said before, it's a fantasy movie, therefore things that don't normally happen are allowed to happen, such as humans flying.
Most modern movies are ridiculous in terms of reality, catching bullets in your teeth, jumping over exploding cars, fly-kicking a pool/billiards ball in mid air causing it to hit another guy in the head, killing him.
It's everywhere, it's to make the movie more
exciting supposedly. Personally I've always enjoyed realism, taking realistic life movies over the likes of Jet Li movies anyday.
But I still enjoyed Advent Children, because it was a fantasy movie, based on a game where equally weird and unrealistic events took place.
Just because the graphics look more real doesn't mean we need to expect real physics all of a sudden
