I have never seen kitties be attracted to the wheels on their own. They always seem to need prodding to use them. I think a better investment would be a cat tree or two cat trees, one shorter and one taller that she will be able to jump on and run up and down. You might also look to change her...
The gabapentin may be causing the slow motility and constipation. That's a common side effect of pain meds in humans and cats. Have you tried Miralax to help keep things moving? It can be added to food or my kitty likes it with a little baby food treat.
I have an asthmatic kitty and while I wish holistic remedies helped or worked, it's unrealistic. I do give my girl a daily dose of an oral antihistamine which helps somewhat, but she still gets nebulizer treatments and steroids as needed.
It looks like a granuloma on her top lip. Those can be very painful, which would cause her eating to be off. They are usually caused by stress, which she had with going to the vet and the dental work done.
My kitty takes 5mg every other day to help control inappropriate elimination. When we first put him on it, it was 5mg daily for 30 days, then 5mg every other day for 30 days. The maintenance dose is every other day. We did wean him off of it briefly, but he had to go back on it because he...
I would definitely talk with your vet. It's possible he's already been neutered or perhaps his testicles haven't descended. He does look neutered to me, though, but I am not a professional.
My vet has stated previously that cats are not like dogs. Dogs will bite at fleas and not get them, but cats will get almost all of them, so she always recommends deworming for tapeworms if your kitty has fleas.
My gray kitty that I've had since she was 6 months old also has a few white hairs on her back. I think it's normal and not because of any trauma or anything. Even my tabby boy has a few white hairs along his back.