Acoustic Guitar Construction

Nubie question...

When done with the top bracing should the bracing and the top be sealed? Is there a preferred process if so?

Most people, like 99.99%, do not seal the top on the inside. If you choose to do so, be sure to keep whatever sealer you use off of the surfaces that will glue to the rim later on or you will be very unhappy down the road when the top flies off!
I recently thought about what would happen if I stuck a rattle can inside the soundhole and gave a good spritz. What would get covered and would it be worth it? It would more than likely miss more than it covered so I determined it was a waste of time. Reaching in with a pad to rub on something might work, but also might not be worth the effort.