How do I modify happiness from the game files?            

I was creating a map of Italy and I noticed a problem. The provinces I created have pratically no population and no economy. How can it be possible that Rome have 488 inhabitants and 300 of economy... even in the Middle Ages it was not so low. How can I fix this?

How can i edit economy and population of province?

You can increase economy of a province "very quickly"... just investing on it. But what about increase population on a province? Does it exist any way to do it? Thank you very much.

I was thinking, a culture map mode would be really cool, like the one on Victoria 2... It would be interesting to see this, and more improvisations on culture system on newer updates, like, making culture be assimilated in more time, so, the game would be more realistic and could last more ages... What do you guys think about this?