Eh, I think that even if dwarves became more reliant on magic, the old traditions wouldn't die out. From what I've heard, dwarves in general tend to favor hard work with hands over airy-fairy spells that do the work quickly.
Love Feiht's "towering" castle... I'm sure someone could live in it, if she shrunk them. Which she would not hesitate to do. :)

Actually, "What Good is a Glass Dagger?" is but one in a series of short stories set in an Earth where magic is fading. Niven also invited other authors to write for an anthology called _The Magic May Return_. In any case, I doubt if it works that way, simply because Feiht and her kin would burn it up so fast no one would have noticed there was magic in the first place. :P

By the way, when Feiht said, "I never get distracted," the force of that untruth (I don’t call it a lie because she can’t remember what she said long enough to know she’s told one) reverberated through the multiverse, destroying several worlds, causing cats and dogs to howl and yowl, milk to sour, the sand on beaches to rearrange itself in bizarre and disturbing patterns, and a fork to fall off a table. :P

Nebra: While there are methods to hold the spell without mage's attention and even obtain some "stable" source of magic for powering it, it is not easy and therefore is safer to build permanent things in a way they don't fall apart when magic stop working. In case of castle this of course requires knowledge of architecture, which I suppose is a point that dwarf is trying to make.

On the other hand, you still can build better castles with magic that without it - for example you can use steel and glass like in modern architecture. Only you probably need a daemon to compute that if you don't have a computer.

Q: What is Feiht's castle made out of?
A: Smek.
Q: What's smek?
A: Smek is smek.
Q: Are you going to give me a decent answer?
A: No.