As promised, I'm reviewing this too.
So - overall I have a favourable opinion. As you said in your message, you toned down the information dumping and it's good, we're discovering Thorüsa one step at a time along with the heroine, which has two major advantages. The first is that we empathize more with the heroine, since we are discovering the same things she is and sharing the same feelings, and the second is that the pace is better and it keeps more of the mystery and enthrallment alive.
One thing is a bit confusing thought with regards to the prologue. In the prologue you tell us that Thorüsa is kind of a hiding place for those who don't want to go to either heaven or hell. A safe haven, assuming you manage to escape your escort. Based on that I imagined Thorüsa to be a different place. You did say it was not like paradise or hell, but still, it's not the same thing as the real world either. But here the heroine seems to have an out-of-body experience, so she's still in the real world, only in a ghost form ? I'm a bit confused here. Is she on her way to Thorüsa, or is she already there ? You seem to hint at the latter but I don't get how it makes sense.
Apart from that there are a lot of good things to be said. I like the part where you describe her experiences touching stuff and going through solid stone because it's the kind of funny, down-to-earth things you *would* think of when in such an ethereal state.
I have nothing much to say about the style, it's pleasant to read, flows effortlessly, so far so good.
At this point this just needs to be longer. The big difficulty when you write original work rather than fanfiction is building the setting, so I'm curious to see how you're going to go about it. What you've shown us of your world is pretty enticing, I'd like to know what happened to Galinicus and what the heroine is gonna do now that she's... well, pretty much a ghost. Wonder if that allows her to communicate with animals and people the way they do it in Ghost Trick ?