I had never seen your analysis, BEM, and I think it's really interesting! Forgive me coming back to this discussion thread after such a long time, but I guess I missed your post in the craziness of the holiday season (a year and a half ago, eek!)
I like what you said about Beth. I think she was completely mixed up at this point, and her love for Mick was mixed up, too. A combination of little-girl hero worship, the I-saved-you, you-saved-me thing (multiplied by a million after the desert), plus a big dose of physical attraction, compounded by the vamp appeal thing.

And for her to find out that "her hero" was in cahoots with the Scary Lady who had terrorized her as a child?!

Well, I can understand why she took a stake with her to Mick's place. She was enraged and afraid and suffering from delayed trauma, not to mention more than a little bit jealous. And also guilty, 'cause Josh was still her boyfriend!

Poor Beth. I don't believe for a second that she'd have staked Coraline if she'd known it would actually injure or kill her. But you can bet she'd have gotten a thrill of angry pleasure to see her tormentor staked and helpless.
About Coraline/Morgan... something occurred to me as I read through some of the older comments on this thread. Many people mentioned how much "lighter" and more fun Morgan was than Coraline had been in the flashbacks. Some speculated that she was just acting, in order to entice Mick, and some suggested that maybe she'd learned some things about herself and life in general over the past 20 years or so. But one thing nobody brought up was, maybe she was "lighter" as Morgan
because she was human! Remember how different Mick was when he was on the Cure? He smiled a lot and laughed, and enjoyed life. And he even acted a little goofy and giddy from time to time. Maybe that's what happens to a vampire when they go on the Cure... they get a little lighter, a little giddy, a little more "joie du vivre' -ish. I had never thought about that before in connection with Morgan.
I think you have an excellent point about Mick and Coraline's relationship. Maybe Mick really was Coraline's first true love. Maybe she'd never let herself fall for a guy before that... and if that is true, no wonder she was so obsessed with him. The evidence Beth uncovered, that Coraline had been stalking her and Mick for months, really adds weight to that idea. You can tell from the chemistry between Mick and Morgan (even when Mick thought she
couldn't be Coraline) that sexual attraction had to be a huge part of what kept them together. But sex alone isn't enough--even great sex. I think the sex was more of a symptom than a reason. The sex was incredible because the attraction was incredible. Like Mick said, it was a fever that burned them up. They weren't rational about each other. And that craziness was really still in full force during "The Ringer"... but I think that changed in this episode, at least for Mick.
Which brings me to the speculation about whether Mick would have stopped (in the shower) if Beth hadn't knocked on the front door. The thing that struck me in this scene was, he was
really focused on "You are Coraline, there IS a cure!!" Yes, she was gorgeous and wet and nude and kissing him like crazy, but he wasn't really as lost in the moment as one might expect. He saw her as his path back to humanity. So I don't see him throwing his clothes on the floor and forgetting all about it. I kinda see him dragging her out of the shower and making her tell him how she did it.
Also, after Beth staked Coraline, his determination to save her seemed to be fueled in great part by the fact that, if she died, he'd lose that path back to life. So... yeah, the attraction was definitely there... but Mick wasn't a slave to his passions this time. He was thinking with his big head (to borrow a phrase from Josef)--maybe for the very first time, where Coraline was concerned.