Well, I think you can make this collaborate with Tier 2 quest: you have an idle mayor at first, but after Tier 2 quest, depend on how you made it your mayor get promoted to give your town a buff:
Church/Trade(for RC): become Bishop/Caravaneer, normally works like a cook, give buff on mood, can start feast that buff mood a lot for a few days, at cost of a lot of food (Festa festa!).
Military/ Mystery(for RC): become captain, give courage and willpower buff,can use all knight’s gears to fight, although much more powerful(You’re not PREPARED!).
Crafter:become High Technician, give buff on fine products and diligence, can collaborate with corresponding craftsmen to gain access to many hidden crafting recipies, from in-red furnitures to costly but powerful moon bow, crafted with steel and silver. When those items are built, craftsmen are working while High Technician are instructing (or"helping" if you prefer friendlier words) at craftsmen’s side(If you have knowledge, you have all the cards).
In fact I want to be a little bit more cohesive to the game’s lore, so Trade and Mystery may should end in “advanced mayors” have powers different from church and military, but so far I can’t come up with one.
Also, If the mayor is player’s avatar, what if he/she dies?