Love the assortment of clamps. Your glass work looks really nice.
I did/am doing my full gut/restore on my trailer. I thought stringers and bulkheads would be enough to keep the hull from splaying, but I ended up having to put ratchet straps across it to pull it back into shape (about 5/8") while I glassed in the deck. Since the deck is in, I've had the ratchet straps off for 3 months and it hasn't moved even 1/8". All that to say, the deck/sole is a structural member, and for my boat, it greatly contributed to the rigidity.
You could probably put it back on the trailer, but you may end up needing to strap it up to get back to your dimensions before/while you glass the deck in.
Regarding other things to do before the deck - not sure where your fuel tank is, but if it's up front and the hose runs under the deck, you may want to put some conduit under the floor so you can pull your fuel hose through it after the floor is down.
