Oh yeah, the game has become a lot more fun now that I learned how to fast travel, no more tedious walking and avoiding monsters on the same paths again and again, go straight to the point, this changes the experience significantly now that I finally am able to focus on the tasks at hand, I enjoy it a lot more! :-D
You really REALLY should introduce the Dark Mirror and teach how it works in-game, I think my idea of introducing it through a side quest given by the hermit at the start of the adventure could work out and the stranger who welcomes the party in the Mirror Kingdom could teach how it works, mention that it is connected to holy places (I wonder why that is so by the way?) as a hint that it is usable in churches?