I might add another idea of mine to this thread: I would love to see "travelling bishops/missionaries" . This coudl simply be done by an event chain, that makes them moce from one province to another and act differently like "try to mission the pagans with force/peace" and following events. The ruler would then get an event chain that would let him decide if he wants to welcome the traveller or expel him. This might lead to faster/slower conversion, death of missionary and perhaps a following chance of him becoming a saints with all efects described in other threads. Also a permanent bishop seat might result of this, if he settles with this one demanding more and more power perhaps.
Also the founding of moansteries would be a nice interesting similar game emchanic that would be fun. With Mother moansteries spreading across the map, with only indirect influence by the ruler. This might also fire reformation events in the curch (within not protestant reformation).
I think religion, missionary work and religious orders (civil ones) played a major part in that timeframe and it would be nice to have something like this in. I think it gladly could be done via modding, but it wouldnt hurt to have some basics to build upon.
Travelling bishops would be especially interesting with the different origins like Irish/gaelic mission, roman mission, Byzantine/Arian mission....
