After receiving feedback from several people, I've come to the conclusion that it is probably best to start my own world rather than essentially pirate Shaddoth's. I've got a basic idea in my head of what I want it to be, with some rather fundamental differences. For one, the system would be a bit more open, with any individual being able to enter instead of just those who were "chosen". Secondly, limited weapon choices when you first enter instead of just getting a random floating weapon, essentially putting everyone starting out on a similarly level playing field (one thing I found a bit odd about Shaddoth's world is that some started with runic weapons while some did not, giving some Hunters a fairly large advantage right out of the gate).
I also intend to make the public reaction to the system a bit different as well, with the dungeon crawlers being something like celebrities.
Believe it or not, I actually hit upon a potential solution to a problem I was having while writing this blog post, so I should be able to jump into the re-write pretty quickly. With any luck I'll be able to have something for y'all soon.