Yes to everything you said, across the board :D
I need to create some sort of decal/permanent debris system that can live on the track to better sell the cut like you mentioned. Along with that, there needs to be an additional effect along with the ones in there now that emphasizes the contact along the side that is scraping. The chunks that are flying up now are just cubes, so some mesh variation will be the next step and possibly some smoke to tie it altogether.
Rumble is a necessity for sure, but I've never actually coded that before... something else I need to look into soon! Appreciate the feedback!