Erm, I should have been more precise. The "absolute" religion power can not go down by *itself*, so after you "wipe out" a religion, it does not lose the absolute power anymore. Which is why you see religions on the charts even after they have no provinces.
So is religious power a set level (number of provinces+temples/spices thrown into that equation) or an accumulated deal (provinces+temples etc. per year or month)?.
I get the rest of what you were saying though.