Living Story progression
I think your missing some other important elements.
Flame and Frost: Introduced us to two new characters, Braham and Roxx. Also we learned that someone unseen had been behind the Dredge/Flame legion allaince.
Southsun Cove: Introduced Kasmeer and Kiel who would and will play major roles as the story continues.
Dragon Bash: Introduces Marjory, makes us aware of a mysterious character by the name of Mr. E who warns us about trouble at the upcoming Effigy Ceremony. Marjory and Mr. E seem to have links to the Corrupt Ministry plot line that can be picked up later.
Sky Pirates: Introduces the Aetherblades and their alliance with the Inquest. We find that, like the Molten Alliance, the Aetherblades appear to have a backer. This time we get a name ‘Scarlet’. Mai makes it clear to us that the Aetherblades arent done.
BotFW: Introduces the Zephyrites who appear to have an item of great value on their airship. Sets up the election in LA for next release.
I think your right about the Sky Pirates/Zephyrite thing though. Thats my hunch particularly since Kiel is now an airship captian. However I also suspect we will find out that the backers for the Molten Alliance and the Aetherblades will end up being the same people.