Well, it is quite hard to find a recent mission that Hexameron hasn't ghosted (or found impossible), so I thought I would give Vagabond a try because it sounded like fun. It was. I had essentially the same experience as Hexameron, perfect thief and all, and I did / discovered everything independently. There was one blemish in my case, however.
On entering Rybolf's room, I found him standing on the table nearly staring at the wine bottle. I couldn't get past him, and I couldn't get him to move, so the only way to complete the objective was to BJ him. I went back a seccond time to see if I could unstick him. I managed to do it with an alert in which he did not see me - he eventuall dropped off the table and resumed his normal patrol, which was easy to work around.
According to some old rule interpretations, a temporary lapse to free a stuck AI is acceptable, so I'll claim victory.
"What we've got here is a failure to communicate", the warden (Strother Martin), Cool Hand Luke