You are talking about the different levels of service if it was booked as a stand-alone train ride. Princes cruisetours use the Princess domed railcars. I have never seen an option to book an Alaskan GoldStar though a Princess cruisetour.
We had this happen. My card expiration date was during the cruise. When we got our new cards with a later expiration date, we entered all the card info with no problem.
I have booked cruises where the excursions were not available at the time of booking. They will come up eventually. Keep checking your cruise personalizer.
I've seen it in the past. I believe it's their computer program. I have always been able to log out of the Princess website and log back in a bit later. Rooms where available every time I did this.
There are 3 to choose from on the Princess website. We stayed at the Parc 55 several years ago through Princess. The hotel was adequate, but the restaurant was fantastic.
My advice with EZAir is to create an account on the airline website. Sign up to receive flight notifications from the airline. We have had many flight changes made by airlines. Everything from departure and arrival times to flight number changes.