You’re not crazy, I think I’m crazy but you’re just a worried bun parent. I know my lop gets bladder infections if she has anything with calculm(kale or other veggies like that). Have you ever thought about getting a second opinion from another rabbit savvy vet?
You mention a slow healer. Is that with her being cut open in surgeries or dentals? It could be since she’s not on painmeds that work for her body, it may lengthen the time it takes to heal.
My lop also doesn’t like to eat hay as her bite is so bad she has to get dentals so often. Have you tried different hays to try and keep her teeth somewhat tammed?
Metacam is a good anti inflammatory for short periods of time as it is very hard on the liver and kidneys. Gabapenton is good for nerve pain. Tramadol is a good pain med but may cause drowsiness. But the other option is buprenex which can cause gi slow down but is an amazing pain killer.
There is this new stuff called Emeraid long sustain which is basically critical care but tastes way better and my buns go crazy over it. A lot of vets don’t sell it yet but it’s been said to be better than criticalcare.
I hope I helped somewhat.