A few small questions that had me curious. Why WAS Ro selected to be a member of the tribunal? I had thought she was considered to be a discipline problem, so I would be curious if perhaps you felt Picard was trying to accomplish something by bringing her in on this.
Well, see, it's like this.
I could bullshit you, and come up with a detailed rationalization... but I really didn't give it much thought. I used her because she was onboard during the fifth season, and because she was a recognizable junior officer.
Pay no attention to the man behind the curtain!
I am the great and powerful Camelopard!
One other small question...I was a little surprised that Crewman Karras only took 10 minutes before involving security. I would've thought there would be someone in charge of the holodeck administration (like the recreation department or engineering) that she would've called first--but maybe I'm wrong about how things are organized.
I don't think the organization has ever been spelled out.
This was a choice I made purely for storytelling reasons. I only had 3000 words to work with, and I wanted to get Mr. Worf involved in 'Step 2.'
I think it's a defensible choice, though. The most important job of any military policeman is traffic control--making sure people are where they're supposed to be at any given time. So I've always assumed that it was Security's job to handle this sort of thing. Someone doesn't show up for work? Call them. If they don't answer, call Security to check up on them.
Same here. Someone won't open the holodeck door? Call Security--especially since Karras probably assumed that Corso was in the middle of a program like Vulcan Love Slave. I think you'd want Security to handle a delicate situation like that.

Final thing...was the reference to the Delomelanicon meant to remind one of the Necronomicon?
Not exactly. The Delomelanicon is mentioned in The Club Dumas by Arturo Perez-Reverte. It's a book supposedly written by Satan himself, and was the source material for another book, The Book of the Nine Doors by Aristide Torchia.
The main plot of the Club Dumas revolves around an attempt to track down the three remaining copies of Torchia's book, and determine which of them is genuine, i.e. which of them includes the Delomelanicon's authentic formula for raising the Devil.
If you're interested, Perez-Reverte's novel was adapted as The Ninth Gate, directed by Roman Polanski and starring Johnny Depp.