I already posted my suggestions in other threads, I will share them here again as people seemed to like them.
- Missionary conversion scales with autonomy. 100% autonomy results in 0% conversion strength. Would make early conversions more difficult as you will want to avoid rebels and raise autonomy. Later on you can convert more as you harsh treat rebels and reduce autonomy to get absolutism, nice synergy between those two.
- Religious ideas no longer give -25% culture conversion bonus but the ability to convert in territories.
- Adapt the muslim center of faiths in trade regions. Any religion can send a missionary to any trade node as long as they have of 50% trade power in the node. A nice buff to tall play, trade ideas and the new mechanic to upgrade trading ports. Also more historical accurate, as trade was key in spreading religions.
Let me know what you think about it and if you actually prefer those mechanics rather than just disabling conversions in territories.