Welcome, John.
Regarding priming, opinions are all over the map. After spending way too much time pondering and researching the priming issue, I settled on this: For mating surfaces in the interior, I roughened with red Scotch Brite, wiped with acetone, and primed with self-etching primer from a rattle can. If I inadvertently scratched the alclad where it didn't contact another surface, I used the above procedure. I also primed everything that's not alclad. Yeah, two-part epoxy would be better, but for all the stuff hidden under the skin, I think what I did is good enough.
Enjoy the build.
Jerre