Re: hull quality?
Lots of ways to measure "strength". Sorry to nitpick, I am a retired Coast Guard Marine Inspector. Composites were a specialty of mine. When a builder cuts a hole in a boat for a through-hull fitting, sometimes they save the plug from the hole saw. That way you can see teh actual layup. Otherwise, if you want to see what kind of layup ( woven roving, scrim, chopper gun, biaxial cloth, prepreg carbon fiber, etc) all you can see is what is on the outside, or inner layer. If you can look at the exterior and see the layup, the gel coat is too thin!
Fiberglass is at its strongest in a curved surface, weakest in flat areas. Big flat areas need additional support to prevent flexing and failure. If the deck flexes, or the hull sides, look elsewhere to buy.
Don't get me started on encapsulated wood...email me if you have more questions.