Agree with everything except the survey part...Besides, you'll want a survey done as close as possible to the date on which you purchase the boat. Things may have changed since the last survey was done.
Just to clarify, I am not suggesting you rely on the seller's survey. I am suggesting you first obtain the seller's survey before you make an offer, then you obtain your own survey. Ideally, you end up with 2 surveys, the PO's and your own.