Oh jeez, this conversation right from the beginning huh? Well, it seems we can make a decision about the door after the service, so I think a utility spell would be useful. Maybe we'll get another Identify so we can upgrade it?
As for the door... we've gotten a lot of hints throughout our journey, but it's finally time for things to be clearly laid out. We've heard there's a great reward for any Chosen who defeats all nine floor monsters they encounter, I'm sure we're about to find out what exactly that is. We'll find out what (or, I suspect, who) the final floor's floor monster is. I also find it interesting that we're making this decision now, at the beginning of the floor. I guess the decision we make here will determine the trials we have to face.
As for Dahlia, I'm curious to see what's changed. It probably has to do with the fact that she trades boons for fetishes that can impede the Chosen's judgement and fighting abilities, but those are meant to be a small long-term risk. That won't be nearly as much of an issue now with the end in sight, so maybe the conditions have changed? Guess we'll find out.