Fishkisser, the old saying "if you have to ask you can't afford it" seems to fit pretty well here.
You have identified a fairly long list of problems that you are already aware of. The next question is: "How many more problems lie undetected?" Unfortunately, the only way to determine the answer to that question is to purchase the boat and find out for yourself. That, my friend is a very expensive answer.
Given your admitted love of river fishing you would probably be better served buying a good used aluminum driftboat to which you could add a kicker later for putting around on the Sound. Also, a small sled could serve you on the rivers as well as the saltchuck.
Regardless of your decision you will get more bang for your buck if you wait until the off-season (Nov. thru Feb.) and shop the want ads (Seattle Times, Little Nickel). You might also take a look at Three Rivers Marine in Woodinville. They are a class outfit that stands behind everything they sell be it used or new.
Good Luck, Nelly