"I would rather live my life as if there is a God and die to find out there isn't, than live my life as if there isn't and die to find out there is."
~Albert Camus
I've had great luck with using glue only for projects. I finished a basement one time by gluing styrofoam right onto the block walls, then gluing drywall onto the foam. No nail holes to mud over.
My contention is that if you plan on removing the cedar then why put it up in the first place?
I grew up in an old house, circa 1930, and there were several places on the walls that had removable panels to access plumbing, in case a pipe leaked. Back in those days walls were "three layer" plaster over oak lath. Cutting a hole in a wall and repairing it was a big deal.
Later on in life, working on homes built after the development and acceptance of gypsum board, I learned a different philosophy. "Drywall" is considered a finish material, and is easily removed and replaced. If there is a problem with plumbing then you just rip into the wall and repair it later.
Its just two different philosophies of design and renovation.
Well a nail gun would sink the nail deep enough so that it wouldn't interfere with the tongue and groove. If you're using a hammer, you'd have to go back and use a punch to set the nail or it would be in the way, since you're supposed to put the nail in near the tongue so that it's hidden when you're done.
And I agree glock. I'd glue it up. Expansion and contraction from the home getting warm and cool might loosen up some of the boards over time. If they're glued, they're staying put. I wouldn't ever plan on taking it out. If I did, well, no big deal to rip out the dry wall and slap up new stuff. A closet would be a piece of cake.