I dont see a problem with this new kind of border expansion, however I think it goes way too slow and I agree with you; religious buildings shouldnt be the (only) factor that expand borders, especially since religion isnt even in the game. But I dont think its of any use to try to change how that works, just speed up the "tile get".
You can buy borders, but it gets a hell of expensive after a while and I hate to do it other then those selective "resource tiles".
