No goop on the gaskets, always a good idea to use anti-seize but not sure how necessary it is due to the extreme heat. And you have it right. If you see any warpage, the machine shop will re-deck the surfaces for about $60 or so. Its a really good idea to have a flat surface there. If you do that, bolt it together on the engine as you describe, tighten down the intake to the exhaust, but when you take it off to have it surfaced leave the intake and exhaust tight to each other, then take the whole thing to the machine shop. Don't forget about the three alignment rings.
