- Forts should stop adventurer/raider movement, unless fort is destroyed. Fort fortification level would need to be tied to appropriate techs. Includes all of them, even these 'non-hostile' bands of hundreds or thousands of armed peoples.
- Male children in dynasty (or possibly just offspring) of liege should be able to become commanders (& receive honorary titles) at 12. Skill wise, you should have better commanders, but there would still be the prestige, piety, & events that may make it worthwhile. This wouldn't have been uncommon historically in time period (ofc things like loyalty would figure in there, which isn't as much of an issue in CK2 since we can 'see' how loyal they are).
- Women should be 'adults' and able to marry at 14. 16 is awfully late, considering era of game.
- Ruler should be able to transfer duke vassals to whomever they choose, regardless of de jure kingdom they belong to. If I have a duke ruling the duchy of Barcelona, I should be able to transfer this person to, say, the Kingdom of Aquitaine -- instead of being forced to revoke the Duchy, then give the Duchy itself to Aquitaine. Even if I held the 'proper' Kingdom for the duchy, I should be able to assign it to whomever. Presumably you're punished enough by having the internal conflicts because of opinion malus from the person that is 'supposed' to have it.
- When a direct vassal goes into debt, they should request a loan from liege to take them out of debt (if liege has enough gold). If debt isn't repayed in x period of time, then it should give liege reason to revoke titles. Having half the Empire turn into a den of thieves happens way too often & taking any action against it as things stand now will usually result in some severe negative opinion. I suspect most other vassals wouldn't want a bunch of highway robbers bordering their territories either.
- Courtiers should utilize their gold on useless things, instead of just hording it. The game doesn't even need to say what it's used on? In recent game, I found some lowborn Han commander I could invite to court with nearly 20,000 gold, ~1000 AD. I think with this funding, the guy wouldn't want to be invited to my court to just sit around as a courtier til he dies.
