The Labyrinth's Constitution seems to have some pretty significant bombshells in it and I'm surprised they haven't really been brought up yet. I'm starting to get worried I'm reading too far into things, but, well, here goes for wild theory-crafting:
Fragment D
The Labyrinth shall pull in people in accordance with the Master's specifications, from whichever location is appointed by him.
Unless otherwise stated, the Labyrinth shall pull in lost beings located anywhere under the firmament but no deeper than the surface of the Earth.
Reading this a little less than literally, an additional contract could effectively give the MC the absolute power to summon anyone he wants, from virtually anywhere (even somewhere in the afterlife), to the hotel. There are quite a few ways that power could be used to serve the story, and a potential resolution to at least one person's quest.
Fragment E
The Labyrinth's fauna, flora and geography will act as to bring the prisoner suffering in whichever way is possible.
The Master may, through contract, determine which forms of life the Labyrinth may spawn and what behaviors they may display.
Again, less-than-literal interpretation means a contract could in effect allow the MC to purge or pacify virtually all the creatures of the valley. In his encounter with the skinned effigy, it was strongly-suggested that he can already command them to his will. If that's extended to the entire valley, the MC could effectively nullify all potential dangers to Asterion.
And here's what I think is the biggest one I've noticed, which doesn't mean much on its own, but depending on where the story goes, is a very peculiar opening to a long-shot potential resolution to the entire conflict of the plot:
Fragment B
The Master shall receive ownership of the realm. He may transfer, sell, borrow and bequeath it to any individual born of human parents.
The MC could lend his position to anyone born of human parents. Not an important article on its own, but then comes Oscar, who may, in fact, be a minotaur born of human parents. If that turns out to indeed be the case, then there could be a master who is also a minotaur. There are a lot of ways that could potentially flip the story on its head and, for instance, impose contradictions on the contracts binding Asterion that could ultimately invalidate them.
All of this is just wild speculation on my part, but it's been bugging me and I'm on break so eff it, I figured I'd share :)