I believe the parking charge is $20 per night.
You still also have to pay the resort fee even when using points. I think it is $28 per night.
We too are DVC members who are staying a few nights at the Swan in April on our Starwood points. Sometimes there are never enough DVC points.
We choose the Swan which is a little more expensive then the Dolphin. The Swan was 12K points a night and the Dolphin was 10K. The Swan is a Westin and I think the Dolphin is a Sheraton. We personally prefer Westins. The Swan is also finished its renovation but I believe the Dolphin is still working on theirs. We definitely wanted a renovated room.