I like this a lot. There are a lot of questions about ghosts! I’m assuming that’s what this world is all about. The ghost storylines may crowd out others, turning it into a mystery. Not saying that’s bad, but that seems to be where you’re pointing.

I also love the idea of this being the second act of a multi-generational campaign.

Maybe when “time passes” a few times, switch to a different world? Same location, of course. Might be worth stealing some mechanics from Undying.