I can see lots of potential abuses in this, especially for money-funneling/banking purposes. Religions are not intended to be money-makers, or to be able to generate large cash flows without significant donations from the nobility. I wouldn't mind seeing religions able to generate a small but steady cash flow on their own. But I don't think I'd want to see religions become independent financial powerhouses. The game just isn't set up for that kind of thing.
