- The entity possessing the Event Horizon has the power to revive the dead (in Weir's case) and warp reality. When Miller blew up the ship as it entered the portal, who is to say that the entity couldn't reconstruct the ship and revive Miller, Weir, and the others, to torment for eternity?
- Miller blew up the tunnel connecting the drive core (where he and Weir were) to the forward decks (where Starck and Cooper were), which were intended to serve as a lifeboat in case of emergencies, in order to cut off the core from the rest of the ship and save what was left of his crew from the Fate Worse Than Death that awaited them in the hell dimension.
- The lifeboat section? Still part of the Event Horizon, cut off from the core or not. With people in stasis aboard to play with, even if getting them to hurt themselves is not immediately an option... No wonder their nightmares. And, possibly, it acting like the good little liferaft until rescuers come aboard, too.
- A dimension where none of our physics work, called "a dimension of pure chaos", would wreck havoc with our bodies—especially brain chemistry—at a quantum level. No wonder people would go batshit crazy—imagine having your entire body infused with drugs, made from your own chemistry and more. It doesn't quite explain the more supernatural stuff, but crewmembers going berserk and attacking each other? Real-life drugs have had that effect, and altering brain chemistry itself, if not outright killing you, would make you less than human.
- Actually, it does explain the more supernatural stuff as "pure chaos", by its very nature, is capable of anything. Including transforming a machine into what we would consider a true lifeform (one as tormented by said chaos as its crew) and granting it psychic power through the process. On another note, this could count as another tie in to Warhammer 40,000, as this is exactly what was hinted to have happened to the Iron Men (and AI in general) toward the end of the Dark Age of Technology.
Fridge / Event Horizon