So I was all set to landscape around my AGP with gravel and river rocks(along with corrugated pipe)
and I read in multiple places to avoid gravel. What can I use to backfill the one foot ditch around half of my pool. Id like to do this weekend any advice would be appreciated.

Mine is backfilled with gravel and do not see why this would be an issue, if you are going to backfill anyway. I can't see other materials being any better for the wall surface. You may want to protect the steel wall surface from scratching with some landscapers fabric, before backfilling, but that's all I can think of

What type of gravel did you get ?
I just went to lowes and they recommended a sand/gravel mix. I guess the logic would be that whatever you get you want it to stabilize in a year or two so if you have to drain the pool it wont collapse the sidewall. I no lovger have dirt to fill in so thats not an option.