Have a similar situation with my 30+ year old Foxxx pool walls only without the sharp thingies and my rust doesn't seem as bad as yours. I don't know of anything to do except wait until the liner needs replacing and then evaluate the situation and fix it. My liner is 11 years old and that's my plan. I think mine is just surface rust and maybe a good sandblasting and epoxy coating or something like that would be the fix. I'm curious to hear suggestions too.
Al