Regarding the question of the passage of time, I canonized it somewhat in one of my earlier posts. It's definitely in the upper billions, but I'd say we're still about 300-500 million away from catching up with where Earth would be. Keep in mind that Galbar isn't fully geologically formed yet and life is confined to just a few places.
On the topic of Zephyrion and this Pantheonic Empire, as you'll see once mortals start popping up that he's very much a fire and brimstone sort of god. He has a short fuse with the other gods that anger him, so you can imagine that he has even less patience (as in next to none) with mere mortals. I think in his sheet I also mention that he's rather arbitrary in his dealings with worshipers. He picks favorites and doesn't act very predictably.
@Double Capybara Care to share the 'dangerous idea' that Ilunabar is afraid to voice?
And she just suggested that Zephyrion build giant instruments for the sake of music, or would they have some sort of purpose? I'm thinking about whether Zephyrion might realistically take a lesson from Vestec by making a bunch of instruments that can wreak all sorts of havoc. A Horn of Doom that kills whoever blows it as well as any that hear its sound, a Conch of Fury that summons a hurricane...