Hi Bill,
Read all the PG reviews you can find here as they are a wealth of information. We gained many "insider tips" before our first PG trip - things they don't really tell you on the ship - like ordering drinks at the dinner table as you have already learned. Also, you can special order anything you want for dinner - unless they don't have it on the ship, they will make it for you! You just need to order with the maitre d' the night before.
If you haven't already found it, there is a great review by Susan W - one of the few I've seen on the Marquesas itinerary we will be sailing.
Susan W\'s Review of PG Marquesas When you board the first afternoon, take the time to "take care of business" as you explore the ship - get your snorkeling gear, make restaurant and spa reservations, ask at the reception desk about galley and bridge tours if that interests you - the ship will be less crowded in the afternoon...not that it ever feels crowded, but we were able to get all that done very quickly and get started on our relaxing!
We did not use the casino so I can't help you there. We did not attend the anniversary party but we did see it as we were watching the sunset and some dolphins playing near the ship. Those who attend it always seem to rate it highly. I think you will be glad you have water shoes - the sand is not always as fine as we may be used to in California or Florida, and sometimes it is very hot. As was mentioned previously, there are sometimes sea urchins to step around.
Are we going at a good time? Well, we went about the same time last year. We knew that December is considered the "rainy season" and there was a good chance we would get rain. We were very lucky - the day we arrived in PPT was pretty rainy, but that was it except for an occasional quick (about 15 minute) shower and one downpour that happened at night. The mid-day showers were actually kind of refreshing. It was warm and humid as you would probably expect, but there was often a breeze and the rain did not put a damper on anything.
Feel free to ask more questions as you think of them!
Dena