Building an Empire

Alright, a few of you are probably familiar with the fantasy states game I intend to run during the end of/after Crusade on ChocPi by now. First off, this is not the final signups for this game. This is the signups for institutions, but mostly general worldbuilding.

What is this game?
So you know states games? They are turn-based economics and diplomacy simulators that focus on generating as much salt as possible between friends. This is that, but with a few twists. Instead of you all playing wildly different countries disconnected from each other competing in the Great Game, you will be princes and dukes under a toothless Emperor in an empire filled with many competing interests - including powerful non-state institutions spread across the country, making up for their lack of hard power with wealth or influence. Since Spheres was such a success, we're going for a fantasy setting again. But we aren't playing that yet.

Well what is the point of this thread, then?
Working out what country we're playing, and who gets to be the institutions. This being an asymmetric game, we need to work out who the institutions are before regular countries can be designed, since for example, the official religion of the empire may matter when it comes to designing your nation. This will limit your creativity a little when creating the princes of the empire later, but it will also tie you all closer together and prevent you from hoarding your own cultures that nobody else has a stake in.

So what are we doing here?
Two things. One, suggesting ideas for worldbuilding the empire. Two, signing up for institutions, if you like.

For worldbuilding, just come up with ideas! The empire is human-ish and somewhat mundane - enough so that the politics line up with what humans would do, or at least be able to understand without having to pretend to be emotionless molluscs. As for its cultures and traditions, and any cool ideas for individual places or people or the like, you are free to write up whatever you feel like. As for what goes on beyond the borders of the empire, that's mostly down to me, though I am open to ideas and suggestions.

For institutions, consider this - there will be most likely three, possibly four institutions, since I'm aiming for 8-10 players and want the majority to be princes. Two of the institutions have to fill specific roles - one needs to be the organized church, and gets to decide the religion, and one needs to be the wizards guild or equivalent, and gets to decide the magic system. The last I'm leaving open, though suggestions for being the secret service or the adventurer's guild have come up, and I was imagining there being some sort of stateless merchant guild option - though equally people might want to play trade city princes instead. If you're aiming for the open slot(s), you can apply with whatever you like.

I'm probably going to favour people who have played a states game before for the institution roles since they are a big deal in how they are gonna have to constantly interact with everyone else. Don't let this stop you contributing ideas though! Both me and whoever gets picked to play the institutions can still agree to alter the religion/magic/whatever to incorporate the best ideas we all collectively come up with.

That's all there is to it. This is just a little worldbuilding for now. Have fun!