Modding Building boni

Well most of you probably know the problem:
If you choose which temple to build you basically have the decision between the happy temple a temple that gives a good bonus and verious temples that either give tax boni "public order" boni or Moral boni. you basically don't have any chance to actuaqlly choose a tample but rather always take the temple with the usefull bonus exept when this usefull bonus is rather unimportant for that settlement.
I don't opt for higher boni in the real mod as things like weapon upgrades from the temple or large tax boni would be rather silly and fantasy like but still I'd like to have to decide if I want to collect more taxes, or boost the military etc. and rather not "have to" burn down old temples that don't give any bonus(still I don't do that because my Governors don't know that some don't work).
well that's why I wanted to mod the EDB to turn public order -> law moral->exp and multiply the tax bonus by 5(afterall the Clerk alone has a 10% bonus a expensive building can have a similar bonus)
Is there anything I have to keep in mind apart from backing up and not to give a faction +1 exp twice rather than +2 once?
are changes save game compatible and is there an other file I have to mod? and where do I find the public order bonus(the one that does not work), Is it the loyality bonus?

and finally are there any of you who have done something similar to their EDB?

thanks in advance