Numbers check out. The backstory is also good. A church fits 100% in a setting with many diverse axioms across the land.
I have a lot of stuff written up for what's 'up there' past the mist-filled sky. Expect telescopes and astronomy in general to be a huge part of most church traditions you will find (you don't necessarily have to fit this into your character's own practices but I'm just mentioning it).
I had thought out the religion as seeing the stars as sort of demiurges in the gnostic sense- being manifestations of the divine that had created the world and humanity, blessing them with the mist and magic. Where to see beyond the mist is to forgo affairs of the world and to peer to the closest thing they have to the "true" divine. The church I had thought of corresponding each rank/role (order?) in the church hierarchy to one of the stars, along with black for the non-clergy still working in an official capacity in the temples. Saints would be those in the clergy that had helped propagate the faith and push the church forward in some significant way. The Calatorum being founded by a number of Saints that had composed a number of rather cryptic holy texts (possible name of Velus Anima? I'm bad at Latin) relating to the divine and humanity.
Just some thoughts, I don't want to impose too much on a pre-established setting.
One thing to note: There aren't a whole lot of stars visible in the night sky, even in space (most of the stars left in the universe are red-dwarfs as those are long-lived...). There are eight bright "planets" which shift around in the sky (seven colors of the rainbow and one white) which are treated as "stars" in that they are the main pinpoints of light visible with the naked eye, although telescopes are not unheard of.
There is no sun. There is a glow that makes up the day/night cycle, which usually faces the cluster of colored stars in the sky, but the glow itself is primarily emitted from the mist. In the upper atmosphere, imagine scores of yellow motes which blend into a haze as you descend to ground level.
So long as you fit within the setting's physics and parameters you are free to create societies and social orders. The main thing I would steer clear of is the named cities themselves; you can be associated with them but you may want to avoid having a monumental role in the city's history (a minor role is fine). Best solution would be to create another prosperous city that made contact with Inberlin some time ago. This is if you want the Calatorum to be more influential.
Worked on my sheet.
I have to sleep so I'll take an in-depth look tomorrow. I know this is a bit odd after I went and explained the stars to Qassius above, but I think character bios deserve special treatment.