Devilman, I Think you already know the answers to your questions (gut feeling) and are just wanting reassurance here. On my transom adapter all the bolts that are able to go through do and use fender washers on the inside of the transom + a smaller washer. I know on mine the bottom couple are srewed blind into the keel and can not be bolted through, so they are just SS screws about 1/4 x1 1/4 maybe 1 1/2. On the seats and hardware ect. I personally like the dab'l do ya routine. but if this is incorrect or bad I would like to know why. Good luck on your boat. sounds like your very close to getn' her wet. R.B.