I can always get my TC close enough with 2×10 blocks. Sometimes use camper removal Jacks as stabilizers in high wind situations. Visit Giant Rock near Landers, CA at your own risk.
I enjoy "real" camping as much as anyone, heck, I used to "backpack" camp more than any other kind. I once sat out a summer monsoon in the Mohave Desert for 18 hours. I'm glad I didn't camp with my dog that trip. Storms are much more doable in my TC....
If exposed to weather, I would also think about using stainless steel if they may ever need to come out again. Plain steel screws will rust to almost any material, even fiberglass. When I replaced taillights and running lights on my '90 Western Wilde...
His problem is solved, good for him. But a tip my father gave me concerning valves is to always open them completely, but then turn them slightly back towards closed. This is especially important for you main "gate valve" supply shut off to your fixe...