Parking at a resort to use that resorts' services (dining or recreation) should be no problem...its only an issue if you want to go to the MK while leaving your cat at BLT/contemporary. As an alternative, you can take any MK bus and walk to BLT..
My boating tip, is get the pontoon. While we didn't need the full seating capacity, it was really nice to have the extra shaded seating capacity.
You can also do the entire loop around 7 seas and around the Bay Lake island in less than an hour. Our charge was pro-rated, so we were only charged for ~50 minutes, not a full hour (plus the great AP discount)