Peggy, great questions regarding Meadow! She is very sophomoric this year, locked in a fairly common 19-year-old's crisis of "separation and individuation" from her family, to put it in our lingo. Last year she sampled escape through multiculturalism in her misadventure with Noah but ended up in a frightening identification with Carmela through her love affair with Jackie Jr. This year, she is trying once again to "flew dah coop" to Europe, ending up with late enrollment to Columbia in a philosophy course on morality. So for now, she seems to be dealing with her separation crisis by staying close to home, as Melfi noted about her, while arming herself with more "in your face" morality polemics for her wayward family. It's a "compromise formation" that many bright youths make at her age. But still the jury is out on where she will end up, making her one of the season's most exciting characters. Let's not forget that college students often go through reincarnations every semester.
Meanwhile, I think you are being a bit too hard on poor Adriana. Sure, she won't be taking Meadow's seat at Columbia, but her being taken in by Danielle speaks more to the astonishingly effective "vertical split" double life many undercover cops are able to lead. And having worked with them, it's one that can be extraordinarily devastating to themselves and their families. I think that Danielle was just that effective in setting aside any trace of conscience of her own, and therefore being able to unambivalently play the role of concerned best friend while setting Adriana up for a fall. There is a treachery in this that is the mirror image of the mob, only coming from the opposite of the street, law-wise.