Hello, I have played your game and I really liked it, but here are some things I think you could add.
1. For maps that are based on real world places, you could add a mode where if you click on an area based on a real life place, it takes the name of that place. Maybe allow countries to have their own borders before the start of the game. For countries and regions, maybe set the capital in the real area. This can be for regions, cities, districts, countries, islands or former countries, combining them too, and possibly adding flags. It is annoying that I have to rename all the places when I want them to have accurate names.
2. Increase the number of countries to 200, since it can add more options, also allow scrolling and name searching for size and age lists. Sometimes I want to add more countries, but cannot.
3. Maybe add a mode that allows for a lot of changes to the gameplay, and add an option to create new custom countries in the middle of the game. Sometimes I forget to add a country, and cannot and have to do everything again.
4. A reload mode that has the same countries and placements but reset. Also a way to disable/enable revolts and alliances would be nice, multiple alliances can also be pretty cool.
5. Edit some pre-made maps so they have smaller areas and cover the area more properly, being able to see country borders can be nice too. Make map making more easier to do or add some more maps.
6. Countries could change their capitals for safety reasons, but needs some balancing.
7. Maybe add a mode where you can play with friends or AI with the country.
These are all my ideas, not sure if you can add all of them but these seem pretty good.