Don't really know who made this game, but currently we've got 1 dev and 2 modders that joined recently, mostly on engine side, as the side you're commenting about (scenario) was mostly done by another team (which was lost along with the website).
Almost all the bugs you're referring to were 1.9.5 ones, which was a good 3 years ago. As for the newer version you seem to be talking about the Beta, which is also like 2 years old (we're on 1.10.0.+ full release, and they're not cross-compatible). If you can't get a clean 1.10.0.+ download (without mods) working, then idk what to tell you, as you're alone in that afaik.
The class reset thing comes from one of your mods (KoS age sorting I think). Also keep in mind that (if I remember right) and I don't want to shift blame as I'm sure were
some bugs in 1.9.5 (like Walker), but KoS hasn't been properly updated since 1.8.X (or earlier). It's only been ported since - so it will likely be missing a few bugfixes in the events it overhauls (unless someone properly updated them).
Stuff like blank lists is down to how the scenario people (modders/players) design the events, they were probably expecting to add more stuff there at some point. Events not proceeding I can't really help you with, it's usually a case of calling someone to your office, interacting with them, or some specific conditions, but you're playing an older version and I've not done a proper playthrough in 5 years due to time constraints.