I'll start the discussion with three proposals:
1. State religion- Make a game function to declare a "state religion." Regions with a majority of that religion get bonuses. However, any peasants present of another religion will become "evil" (even pagans!). Meaning that declaring a state religion will create riots, and an enemy priest could comparatively easily cause havoc simply by preaching. Maybe even allow some "tax share" for the religion? Not sure how that would work? This would make religious diversity more difficult, but also help inculcate a stronger sense of the realm as a cohesive unit (think "Christendom").
2. Royal levy- Ruler can exercise a special tax directly on a region while in that region. Meaning that a royal sitting in a rich city could take money directly. This would strengthen the ruler.
I really like these. State religion should have been put in a while ago imho (or should be planned to be added already) and the royal levy is really cool. I've felt that rulers really lack balls in BM. While I think the power of the dukes should not be diminished, the ruler should have some sort of financial backing that doesn't rely on the banker.
