The national focus idea seems like it might be somewhat of a remedy. Personally, I'd prefer to see just one BIG pile of "administrative points" that the player draws on, and instead of the monarch giving these points, the monarch would just give you a modifier for administrative, military, and diplomatic actions. For instance, a monarch with 5 military would give a 25 percent discount to military actions, military teching, etc. A monarch with 3 diplomacy points would give a 15 percent discount to diplomacy actions, diplomacy tech, etc. That way, if you want to ignore warfare, you can still focus on trade or diplomacy heavily.