By "regular" you mean without any of the expansions, right? You should really get them if you haven't, they add quite a bit to the game!
I think that most of the manufacturies are a complete waste of gold in the game. Like, I may build one in a capital or in a very high value overseas province that I want to give a tiny population increase to.
I like to edit the hell out of the game myself. My favorite one was this one where I changed every country to a westernized Catholic Merchant Republic, and the game ended up with the Ming Chinese and the Mali being two of the most powerful countries on the map.
You have to remember, though; the very thing that makes you a nerd is that your enthusiasms are totally unrelatable and non-marketable to most of the world. For example, anime and celibacy. - Seanbaby