My question that NO ONE will answer is:
If one COX-2 inhibitor is bad, then would it not ALSO rule out using any other COX-2 inhibitors such as Omega 3's, Thunder God Vine, Resveratrol, Flavonoids and Bosweilla Extract??
Wow, I've never heard of some of these, not that I'm an expert. I understand what you're saying. In looking at what you quoted, this is the only thing that makes me think that some COX-2 inhibitors are better choices than others:
There are other choices for pain control for our Addisonain dogs: other medications that use other pathways,
Is it possible that Omega 3's, for example, use different pathways that don't affect kidney function and the stomach like the NSAID did, and therefore would be a better choice? I don't know, I'm just thinking out loud here. We don't know what pathways they or the other things you listed use, so we don't know if they'd be better choices. That would probably take some digging to find out.
In the course I took last year, the instructor mentioned that digestive enzymes, when taken separate from food, reduce inflammation. While it was a course for human healing, I wonder if the same is true for dogs and cats. It might be something to consider, if you want to look into it.
I don't know if this helped you at all, but I hope it did.