It seems like my Rosier's disloyalty should have been suspected a little sooner in my first attempt at this scenario. Right after the first time he expressed reluctance to kill the twisted men I had him explore a lair, which resulted in him becoming crazed possessed by a demon. His rage helped be take over a lot of Lanun cities, but he happened to turn barbarian 1 turn before I finished building my first adept to cast Loyalty.
"Special Rules: Rosier must Survive" - I had to kill the barbarian Rosier using Valin before I ever got the the OO holy city, and nothing special happened. It doesn't seem like this rule means much as it is now. I would have thought that his death would make you loose the scenario, or at the very least have some sort of pop-up.
I don't see why the confessor chastised me for not studying the will of Junil enough yet when I had already researched Orders from Heaven (well, technically I just told Sabatherl to research it while I researched something else) and had both Rosier and Valin already. (I think this was right after I tried to use Valin to attack Muirin, but he wasn't brave enough.)