Congrats! You are going to love the concierge experience. You can call Shoreside Concierge a few days before the 130 day mark and they will email you a list of the planned beverage tasting seminars so that you can look at which ones you are interested in and request them with everything else at the 130-day email request letter.
Be sure to include your reservation number in your 130-day email. You can reserve spa treatments, specialty dining reservations (dinner and brunch and requested times), and a specific dining rotation. Sometimes they don't know the options yet at the 130-day mark, but you can always say something like "dining rotation beginning with Tiana's Place" if you know that's where you'd like to be on the first night. You can request excursions, certain Coke-products in the fridge - I loved getting Smart Water and Dasani in the fridge on our last cruise. You can request certain pillow types from the pillow menu as well, though I have not really seen an updated pillow menu lately, so not sure what is being offered.
Without a cabana request needed, there's probably not a huge reason to calculate to the minute when you should press "send" on your concierge email. You should be able to get everything you want by sending it any time between the 130 and 120 day mark. An exception could be a very popular excursion or brunch reservations in Palo since it could be limited by the short length of the cruise.
I have heard that private dining is always included nowadays for concierge families, but I always include the request along with my other requests. The reason is that we were seated with another family for our first concierge cruise (ages ago) and I did not know that we could make such a request. While we enjoyed the other family's company, we do prefer to talk amongst ourselves while eating - so it was nice when we could sit at our own dining table.
Another thing I did not know on my first concierge cruise is that the concierge hosts ARE guest services for you, so if you have gift cards to apply to your account or any requests at all, they will make it all happen for you and you'll never have to wait in line at guest services.
It is an amazing experience, and I hope you enjoy it as much as I do. Have fun!