Hey,
Glad you enjoyed it.
1) Yes, it probably should. The idea was that it would keep the world alive, so if you stopped taking action it would return back to normal. For the bugfixed version of V3 the world-wide changes will be made permanent, I think.
2) Maybe in version 4. I think the best approach would be to use the province system. Each province could have a duke assigned, promoted from one of the nobles in the province. Each provincial ruler would report to the king/queen, and you'd have to first be promoted to leader of your province before you'd be allowed to become leader of your nation. It ties into the current setup, where people in provinces are naturally allied to each other, because of shared industrial concerns, and how civil wars occur by splitting off provinces into their own nations.
We've not touched it yet because it would make the game more complicated, and we wanted to get quality of life and understandable gameplay at least somewhat handled before adding complexity to the system.
3)That's a very good suggestion, which makes a lot of sense. The nobles are supposed to be enshadowing their entire cities, so it wouldn't make sense to have new nobles arriving which are somehow unaffected. We'll try to get that added in as soon as possible.
Age) We were discussing this, actually. "How long do you think a turn is?" I figured it was maybe a season, but my co-author reckoned it was about a week. If we decide to implement some actual time system, we'd need to work out population growth speeds and suchlike. The main reason characters don't die of old age is because I wanted the system to be easier to understand and follow, and having characters randomly die would possibly confuse players, or force them to read huge numbers of messages about character deaths. We'll look into it.
Dark Unity) This makes sense, having enshadowed characters prefer each other as rulers. We wanted the dark empire to still have politics, but it would make sense that you could influence the enshadowed to hate those who are still light. Maybe just a power, which you could use to make all enshadowed dislike all light people a little bit?
Thanks for the feedback, we'll get to work on a bugfix version for V3, then on V4.