Is there anyone out there interested in this game? I'm fairly certain it runs well on Dolphin. There have been a good amount of real time runs done and there is also a segmented run (with another one on the way) to use for inspiration. I thought about trying to do some TAS work myself, but I've been really busy with tons of other speedrun stuff at the moment.
Almost all of the documentation of this game is in this thread:
https://forum.speeddemosarchive.com/post/eternal_darkness_sanitys_requiem.html
The best (and currently only) real time speedrunner has a pretty solid time, here is his channel:
http://www.twitch.tv/zwajken/profile
The most recent segmented run and accompanying info is here (updates of the new segmented run are in previous SDA link):
http://speeddemosarchive.com/EternalDarkness.html
I would likely be interested in helping out in the TAS process if anyone else shows interest. I am involved in several other projects, mostly real time speedrunning, so I probably couldn't spearhead the TAS myself should it be started.