Stress fractures in my boat

I bought my boat new. its an 05 Moomba so the boat is just beginning its 7th season with about 750 hours on it. I realize that Moomba is an economy brand so some problems that I have such as the tearing upholstery was expected. What is really concerning me - and I am wondering if anybody else is having this problem - is the amount of stress fractures that are showing up. The worst ones are near where the swimdeck mounts. Those cracks are so deep that I can see them on the inside of the boat. Also, as some of my bolts loosen up I am finding that they are not bolts at all but simply wood screws drilled right into the fiberglass. The fiberglass around the screws is cracking away.

I am not bashing Moomba here I have absolutely loved this boat in all other respects. But as it comes time for me to consider buying a new boat I am uncertain where to go. My original plan was to get a Supra. Since Supra and Moomba are both Skier's Choice boats I wonder If i will see the same problems in the Supra. What brand boat is safe so far as I can expect it to last many years? Thanks for your input.