Okay, finished the current version. I have enemy at 0 strength, all scenes, all achievements, etc. Here's my thoughts.
Prosperity and prestige need easier ways to increase, I suggest a parade option. Selling treasury and winning big beggar should have 10* the current value.
It's extremely difficult to naturally trigger the bad end, and as it stands low prestige isn't very impactful.
There should be a Battle X Times option, as once I hit endgame I was just spamming that for prestige anyway.
The Bad End Button should let us choose bad ends, or you can add them to the gallery instead.
Storywise, it would be great if both the agriculture and tribal regions could become duchies, and if we could develop the nation into an empire (conquer desert option). These would be optional and affect story route. Similarly, we should be able to be conquered or marry into other nations as well.
Side note: If it was me as queen, I would make a "marry no man" aka either "married to the state" or "marry a woman" option so all of my "illegitimate" children would be legitimate. Especially with all of the lovers, the queen would be an Heir Factory.