you will just have to start calling around to travel agencies. Try asking on the other social medias group pages, I've seen lots of TA's volunteering that they have space available when asked.
There are lots of times that I see a lot more cabins than what you can see on Royals website or other sites. Cruising power gives access to all available cabins while Royals site does sometimes limit cabins that can be seen.
TA's do not hold cabins. They hold space within a category. Royal may hold cabins back that are unable to be seen either on Royals website or by TA's on their booking site in order to fulfill that group space obligation. There are sites out there that do show more availability than Royals site including the site that TA's use to book
That is if you book on board. Next cruise will automatically assign any cruise that you book on board to the TA that you used for that sailing you are on unless you explicitly tell them not to or to assign it to a different agency.
Booking via the website always goes into the guests name
Bookings open Thursday for everyone. They have only sent out the announcement to C&A members however for anyone that sees it open they will be able to book.
That's a unique sailing so really nothing to look at to compare. Just look at the regular 7 day schedule. Any additional shows will follow the same general pattern. You should be able to get a pretty good idea of whether to book early or late seating.
I know lots of people that have had their shareholders obc applied to their 2025 sailings. You can apply as soon as you book regardless of when the cruise sails.