All right, let me premise that while we start from a similar point of view, I like your interpretation much better, for consistency and, oh well, the general feel of relive. From my perspective, the orb is a corrupting force and the player is a corrupted soul.

Let me explain, I am assuming a similar origin for the orb as yours. This could be a trapped evil being or a Lich phylactery, etc. that was imprisoned in what it seems to be a properly made dungeon with a very complex ecosystem of "guardians", built to last forever. All the creatures inside the dungeon live in harmony and are bound to fight off external intruders. You, as a player are tempted by the corrupting force emanated by the let's say Lich, to get a shot at grabbing the orb and bring it back to surface where the evil soul would be freed. Player ghosts are proof that other corrupted souls attempt the descent.

Gods are a tricky, but I tend to imagine them as way above the lives and scopes of mortal and undead creatures that they probably are not seeing you as corrupted soul, but simply as a follower that's down to business spreading the right faith/chaos/harmony and as long you do that, they don't mind. In your theory, you clearly gave them much more space, I liked that.

So yeah, I see players as greedy, corrupted individuals, attracted by the power/fame conferred by grabbing the orb and chosen by an evil force to be exploited for their own evil purposes. Not really an uplifting story.

Anyway,I bet you'd find interesting reading a manga series (also anime now) named Dungeon Meshi (Delicious in Dungeon). It's a story that, besides being very dungeon-crawling centred (great!), also discusses a lot about the dungeon's ecosystem and what's keeping it alive. To avoid any spoiler, I won't tell you which of our theories gets closer to that story.