I'd like to suggest additions as well, if you don't mind:
- Random resources, each with definable bonuses, and the ability to trade them
- Upkeep costs
- Ability to leave alliances
- Non-combative improvements - schools, treasuries, barracks, etc
- Population, which increases with certain factors - time, resources, improvements, etc
Not sure what all would be needed to make this happen, but I would gladly donate what I can to help out, and show my appreciation.