idea list:
bigger and more detailed maps (a world map with the same accuracy as, lets say, the europe map.
ships: ships would make so much sense instead of just crossings, and it would mean you can invade from anywhere even if you aren't bordering it and/or next to a crossing like istanbul or something
'my country mode': being able to make a country completely yourself without the country's AI interfering whatshowever (and without god mode to alter other countries)
power scaling (2 small countries can currently defeat a big one if they attack at the same time, which to me doesnt make much sense.)
limited army size that replenishes slowly after every war (so you cant have infinite battles