Almost all CA glue is a fire hazard with cotton, especially fine cotton fibers.

You can stick a piece of paper to almost any surface with just water, yes. There's nothing more adhesive about drywall mud than dirt mud. That's part of why it's such a pain to work with.

By that logic, pudding is an adhesive. Paper drywall tape will adhere to anything wet.

I tried using it on the exterior of a fire pit ring, with full surface prep and curing in good conditions. It burned off in 2-3 uses except for ~2" along the ground.

Yeah, I've used it too. It's good to like 1200°, supposedly, which is enough for gas grills on surfaces that don't get direct flame contact. It does not stand up to direct wood flames, or even the exterior surface of metal exposed to wood flames, like a fire pit ring.

Yeah, no paint will stand up to fire for longer than a couple of minutes, and give off nasty fumes in the process. Definitely nothing you want in your food.