How to book Stockholm Royal Palace tickets

I don't know about the Stockholm City Pass, but I can comment on your itinerary. You're going to be rushed on the first two days.

We did Djurgården, Skansen, Vasa, and the ABBA Museum in one day, and it was a rush. Skansen in particular is massive. You could spend a whole day there. I’d cut out a museum, but definitely keep the Vasa Museum. It is well worth seeing.

At Djurgården, rent bikes first. As soon as you arrive on the island from the north, there’s a visitor center on the right with bike rentals. Take a nice bike ride around the king's garden.

The island of Gamla Stan is a day on its own. I don’t know that you can fit that and Östermalm into a single day. I'd recommend you hire Håkan Fränden as a tour guide, if that's in your budget.

One thing not on your list that I would highly suggest you add is City Hall. It’s an impressive structure and the guided tour is excellent. You’ve never seen anything like the Golden Hall, lined with millions of gold mosaic tiles. The Nobel Prize banquet is held here, too.

Thank you much! Do you know what museums are included in the Royal Palace ticket?

I don't know. We didn't tour the Royal Palaces. Instead, we prioritized the Royal Armory (in the same building but lower level), which was exceptional. I see that's already on your list. When you go, be sure to see the royal carriages, in a separate section of the Armory (down a flight of stairs off to the side, I believe).

I guess this is the information you are looking for:

https://www.stockholm-card.com/en/

City pass say it's a 200 SEK ticket so I assume it's a standard ticket without guide. I would also assume it includes The Royal Apartments, The Treasury and Museum Three Crowns as all other tickets.

Thank you everyone for the responses!