I agree you look alot more advanced on jumped than on rails. I also notice bent over at the waist thing (but only on heel side. toe side looks fine). It might be why you look little sketch on the approach to the jump (since you started approach on heelside turn). Work on your heelside carve. it will give you more control coming off the jump leading to better control in air. Just learn to carve on your heelside on regular trail or ride half pipe. (pull your shoulder back so as result you are little more upright) It will help you tons on jumps. Just nick picking since your jumps look ver solid. I would have never thought this was your first day doing 3's. they look really solid. As far as rails, I am in no position to give any advice since i am awful.