I actually really like Carolyn.
Yes, she's got some major issues, but as a character she was so awesomely portrayed by Annette Benning -- so shallow and divorced from herself in some ways, but also underlying that invasive aggression and drive and seeming lack of coherence is a real vulnerability and fear that she won't be able to keep her life together... and if she doesn't, she will not be able to depend on anyone else.
(After all, Lester sort of emotionally abandoned her long ago and now has become a loose cannon. He used to be passive, so she took charge, and perhaps vice versa; and now he's just become self-indulgent and self-focused. That Fi that the movie portrays so positively also is actually rather selfish, if you look at how Lester has divorced himself from his relationships in his process of liberation. Lester does not really break out of his selfish Fi mode until he chooses to not have sex with Angela, because he sees her as a real person, with real needs. That is the moment of Lester's true liberation.)
That whole scene where Carolynn tries to psyche herself up to "sell that house"? Wow. I can watch that scene time and again, it makes me want to laugh and cry simultaneously. She is amazing. She goes in there, gets herself going, works endlessly to make the house perfect, plows through the obstacles of the day, gives those sales everything she has... and fails miserably partly because the house sucks so bad and her buyers are sort of lame. You finally see her crack, after they all leave her in the empty house, when she breaks down momentarily... completely breaks down... and then you just watch her, the battered warrior, climb back to her feet, bloodied and bruised, get herself together, and march out to try again the next day.
War vets don't have anything on Carolyn. I find her perseverence impenetrable and yet amazing. It is one thing I've always valued in SFJs, honestly.
The reason she tries to hard to keep everyone in their assigned roles is because she's not yet stable enough internally to keep herself afloat if everything external changes. She just isn't self-aware enough right now to be able to articulate that, she keeps thinking that if she was more successful she'd feel secure OR that everyone else should stay where they are so that her house of cards does not collapse.
The "real" Carolyn is the one in Lester's final memory flashes -- where Carolyn is laughing on the amusement park ride. That captures the person that Carolyn could be, if she is secure within herself and just lets herself exist rather than trying to control every aspect of reality.
In any case, no one in this movie comes out looking good, really, they're all kind of self-obsessed and screwing others over to get what they think they need and deserve... except for maybe Ricky and Jane. They are the EveryPeople in the movie -- they want to be loved, accepted, and understood, but get none of it, and end up having to fend for themselves while trying not to hurt anyone else or USE anyone else.