Re: eternal darkness gamebreaking bug
I wasn't able to find much about this being specifically a bug or anything. Though I did find others pertaining to doors and wallpaper, ect. I saw someone say the a key needs to be repaired before using it on a door and I believe it was the section you are talking about (I've never played the game so I can't say for sure). Whether this is an issue with the rom itself isn't really clear. I checked the comparability on the wiki and it looks good to go. All the roms here are dumps from the actual disks so there shouldn't be any weird changes that go along with that unless say the people who made the game intended it to stop piracy or something (though I don't think it would affect the rom in this case but stranger things have happened).
Beyond that I can't offer much help since I've never played the game myself and the internets didn't give me much to go on.
I've encountered a bug in the rom for Eternal Darkness. During the interlude before Chapter 6 the player is supposed to be able to approach a dresser on the second floor, use the "reveal invisible" spell with the blue rune to reveal a keyhole. The dresser key must be used to unlock it so Alex can access a gun & the next page so that the next chapter can be played.
For some reason, after using the "reveal invisible" spell, I still get the cutscene showing the lock being revealed, but any attempt to actually use the dresser key results in failure. I've tried going back in my saves to see if somehow I missed something, but at this point I'm pretty sure it's a bug that's hard wired into this rom itself. There's no way to start Chapter 6, so this has completely killed my run. Has anyone else encountered this and (oh please oh please) know of a fix?