The whole thing has to furred out and insulated first. And that means that the exterior water management has to be perfect. Drywall is the cheapest wall cladding that you can do, and needs to go over the studs to help air seal and provide fire resistance. After you do all of that, you can put whatever extra 3K worth of wood on top of that if you haven’t realized it’s thankfully out of style by now.

I hope you have legal egress windows. Because life safety in a bedroom is way more important than any decorating.

It's not about decorating. It's about keeping my father in law away from my cinder blocks. He already drilled into the walls & poured tons of cement dust into our house to "fix" stuff. If I cover stuff where he can't see it, he can't tweak out and convince my husband he needs to "fix" things. I'm desperate here.