I'm not sure we can really say Cassandra's stuck in the past the way Kronos and Silas are. She's modern enough to just hire a detective agency to track down Duncan in "Prophecy," after all. It's hard to gauge her mindset since IMHO she's in complete freak-out mode in the Horsemen eps, because she really was not expecting Methos (to be alive, to have wormed his way into Duncan's life) and probably only found out recently that Kronos was still alive.

I agree that Methos isn't what Cassandra says he is, but I can hardly blame her given his current behaviour. And I gotta say, when Methos is talking about Patty Hearst and she gives him this WTF face of complete disbelieve, I kind of assume she's thinking, "Seriously? Seriously? You're trying to tell me about Stockholm syndrome?"

I totally agree with your last sentence, though. I was trolling TV Tropes (as one does) and came across a concept for villains with contingency plans, so that even when it appears they've been defeated, they've actually secretly gained a victory. Not that Methos is a villain here, but it's that kind of agile thinking that makes him so dangerous.