I guess creatures made from dungeon magic is still a taboo. I remember the canary elves said they are ok if eating exotic slime cuisines from the surface but not if harvested from dungeon. Fear of magic poisoning maybe
Definetely not off-screen cause the siblings never met each other before and only met in chapter 1
Expensive is kind of exaggerated I'd say. I'm sure they can afford it just by looking from their house. Don't have to be a grand wedding, just invite a select few
I guess its similar to the clairvoyant girl, as long as she is receiving the signal/power from the tower she can see great distance outside of the border far reaching the empire