Zero percent chance I would paint them. They won't be remotely flat and would look terrible imo. I'd pull it down and use drywall. Good time to add receptacles or insulate bedroom walls too.
I was almost thinking I’d like the texture.
I'm not just talking about the grooves. The panels will be wavy. Once you remove the wood grain, you will see the ripples and probably every nail dimple.
Brown furniture is out and probably walls as well. Painting will make a change but I'd be afraid of warping and flaw enhancement as noted by GG.
I’m thinking of doing 1 room just to see. If it’s bad then I’ll just rip it all out.
I'd just board over the paneling for the ceiling.
Don't you have a tractor? I used to use 3 point hitch to lift as it had a lot more jam than the bucket. Are they in concrete or just pounded in? If just pounded in, wobble wobble wobble, pull. A piece of chain and hydraulic jack gives you thousands of pounds of lift for zero additional cost (or storage).
