Re: New Starcraft,need help!
First of all, that's great looking boat and should give you many hours of fun. As to your question, the only one that can answer it is YOU. In order to have peace of mind, the deck should be pulled up and the stringers "biopsied" with a small drill bit to determine what shape the stringers are in. If the drill chips come out wet and mushy, you'll need to dig further. If they're dry count yourself lucky and reseal the holes. If you're having doubts at this point, join the club....but the boat's worth the effort!
As to the transom, I went through the same qualms with my Skagit but finally tore the transom out completely. Good thing too, as I found that the previous owner had drilled several holes to mount a transponder THROUGH THE HULL, then sealed them with bathtub calk. Combined with age no wonder the transom rotted.
While checking on Seacast, I found at least two other products that were a lot less expensive....by about half. I don't recall their names, but Google "pourable transom" or "pour transom" and you'll find them.
Edit: Your post beat mine! Glad to hear the deck is solid. One of the names was Nida Core I believe. Someone will chime in with the correct spelling.