Parking is $12 a day at the port. You need to pay when you park for the entire time. To park at the Residence Inn you pay $6 per person round trip to ride the shuttle. If you have not checked out my trip report I have a bunch of pictures in there from the Residence Inn as that is where I stayed in September.
The most formal rotation restaurant would be Triton's, what night you end up there depends on the rotation you receive. Also you can let your
travel agent know if you would like early or late dining, this is just a request. Early dinning is around 5:30-6pm. Late dinning is around 8pm. If you have early dinner you watch the show after dinner, if you have late dinner you watch the show before you eat.
Although
DCL designates a night which is more formal which may or may not be the night you are in Triton's. Pirate night has recently been on
Castaway Cay night on the 4 night. Some people dress up on Pirate night, others don't. It appeared to me more people dressed up on the 7 night then the 4 night cruise. Although people still did dress up. DCL provides pirate bandannas to everyone at dinner.
You can book dinner at Palo 75 days out. If you do not get a spot online do not panic. These save most of the reservations for once you arrive on board. You can book as soon as you get onboard. You can also stop at Palo later to see if they have open space or to go on a waiting list. We had booked online for brunch one day and ended up changing to a different day once on board.
As for snorkeling equipment you may be able to buy it cheaper then you can rent it. Some places might still have it on clearance. If you do that then the kids could try it out and get comfortable with it before you go. Which I highly recommend. Some kids take awhile to understand the concept of breathing through your mouth instead of your nose. I know it is another thing to lug then but the kids could get comfortable with it, even if it is just in the bath tub.
As for pictures I always asked somebody to take a picture with my camera and didn't buy any. Lots of people had them take pictures with their personal camera. The only difference is most of the pictures they take have a graphic design around them or on them. I know if I had kids though I would probably think differently. I truly wish they would set up a photopass system and you could buy a CD full o pictures.
I hope this helps. If you have any other questions ask away.