re: "Free boat" seaworthiness
Seriously don't take it. There's no reason at this point to take a serious fixer upper at this point unless it offers you something that the cheap but not free boat doesn't. If that thing ever sails you will have spent far more fixing it than you would have buying a good cheap boat to begin with. It's very expensive to buy anything at all for a boat so you will be in for several grand easy no matter what. You could spend that money on a boat in better shape that would just sail.
You have to pick the boat you save. You can't save them all. So pick a healthy one.