Great as all the others have been. If you wanted to list ALL of the updated renditions in AC, Great Northern Cave plays during Kadaj and Rufus' conversation on the building.
One correction, which I'm almost loathe to make as everything else you said about it is spot on. But that particular version of the FF7 Main Theme actually plays during the scene from Case of Denzel. Where Denzel finds Cloud's phone, calls Tifa, passes out and is found by Cloud.
During Cloud and Marlene's conversation, a simple piano rendition plays.
I LOVE Beyond the Wasteland, and my favorite part is the sound of the violin bows hitting the strings right before the action bit kicks in.
I feel pretty stupid for not ever realized Violator is Shinra Corporation. For some reason I always just assumed it was referencing Fighting and didn't think more on it, nice call.
It's amazing how similar some Dirge and XIII tracks are. You could drop most of them in the other soundtrack without noticing. Fight with Shelke always stuck out to me as sounding
very XIII.
Good analysis of Dirge too (though you missed my personal favorite, Silent Edge. But that's mainly for how atmospheric it is, I don't think it calls back to any other tracks), I never paid too much attention to Calm Before the Storm before.
The two Gackt tracks I think are the only time Square has stuck otherwise unrelated pop/rock songs into a game and actually have it mesh with the game. And I like both of them as well. Longing often gets overlooked.