I'm all for conflict, and lords who decide they want to tax the religions is all well and fun.
What I'm not for is making it impossible for religions to strongarm lords into making them exempt from taxes without requiring a non-trivial amount of work. After many years of painful experience, things in the game that require large numbers of people to do something once a week (or once a month) don't happen. They just don't. People get sick of it, or forget, or don't make it back to their regions.
An option to tax temples = awesome. Forcing people to tax temples = painful.
I completely agree.
While religions might have been tax havens for some, legit religions are costly. Indeed, too costly if you ask me. Traditionally, realms sprung up artificial religions sometimes just to keep in check foreign faiths... After playing the religion game *a lot*, I consider this to have been a poor strategy. Costs thousands and thousands of gold to properly set up the religious infrastructure of a medium-sized faith, and months and months of nothing but preaching to have good follower %.
A simpler solution: just arrest the foreign priests when they enter your lands. Just costs a small police unit, which pretty much everyone can carry around (except traders and priests). Considering how most religions have very few priests, and that indeed a good number of old faiths have died because they lost theirs, this solution takes very little effort and gold.
Some people will say that "priests are powerful", and name stuff like "Claim region" and the like. With the amount of investments required for a religion to work, you may as well ask for all these funds, send it to the family home, and just outright buy the region... Getting the required follower % in hostile lands for meaningful regions and next to impossible anyways, and claiming a region without the support of the army (which you have to, since they'll try to stop you) is likely to lead to the region revolting too.
Taxing temples will just make the religion game that much less worth it. I can understand taxing temples of religions that aren't yours, but having one's temples taxed by one's own followers? That's just pressing the financial burden past the tolerable limit.
