I'm curious to know how to use {DI'ruj} in a sentence. Can we use it to make existential statements? For instance, would something like {DI'rujDaq 'IDnar tu'be'lu'} be interpreted in the sense of "Magic doesn't exist/is fictional"? Is {DI'ruj} a location, can it even take a {-Daq}? Does {'IDnar ngaSbe' DI'ruj} work for the same idea?

I wouldn't automatically assume DI'rujDaq makes any sense, unless you're talking about a science-fiction story in which characters are hopping between realities. Your second version is safer for that reason.

Such a word depends on a conceptual metaphor of "reality is a place," which we don't know Klingons share. Maybe if there are hints of this particular conceptual metaphor in canon we could be more certain of it. I can't think of any offhand. Klingons might conceptually consider reality to be a state rather than a place, for instance.

-- 
SuStel
http://trimboli.name