I've never moddeda game but have enjoyed playing many of them. In the interest of a more historical mod, I was wondering if these things are possible:

1) Have date triggers for all buildings so you can't get too far out of sync with history.

2) Implement "shadow" factions for nations so a proper Protestant Reformation (revolts) could be modelled into a game that extended until 1700 or so.

3) Get the AI to use naval invasions

4) Implement a procedure by which a general/family member could increase their piety - such as making a pilgramage.

5) Build in a better representation of the Feudal system by having generals/family members willingness to leave their "homeland" based on what you've done to gain their loyalty - such as build buildings in their province. This would require those characters to recognize someplace as home.

Other things I suspect are possible because they were done in RTW would be:

...an AOR system that required time to pass before you could recruit the same units you can make in a "home" province.

...greatly increase the number of rebel provinces at start to include the vast number of historical regions currently left out. This would include reducing the economic worth of most provinces so you needed more to earn the same $$$. It woul also make the castle/city choice more meaningful.

I'm curious if these things strike others of you as valid changes towards a mod thats more historical ?