If they're used in the winter they all do that sir!
Stainless bolt kit will sort the fixings problem. Paint brush, black paint, fine wet & dry will sort the boot scuffed frame. The only expensive bit will be the wheel corrosion around the spokes, not easy or cheap to fix. If you don't mind it being there it won't cause any problems within the next few years/50,000 miles.
Cotton bud dipped in ACF 50 and dabbed around the spoke ends will slow down the corrosion under the paint.
Years ago bikes didn't rust this easy & there was no such thing as acf 50 etc.
Sad really