Ah, yes, I do remember that about Samantha. "They don´t call it a blowjob for nothing, honey." But I thought you were talking about class commentary, which, Miranda's boyfriend Steve aside, is mostly elided in the series.
Would you have written Samantha differently if you could? I found the criticism of her just being a gay man in a woman's body extremely compelling; she never seemed to face any of the dangers a woman would realistically face in being as openly promiscuous as she was. She is also kind of hilariously square most of the time. Any time some actual kink comes up, she absolutely freaks out.
eta - I think the backdrop of Samantha, as you presented her, is to argue that sexual politics is based on economics, not biology. I partially disagree. I think economics plays a role, surely, but there are sexual behaviors that tend to cluster around gender biologically. I don´t think gender is entirely socially constructed, though social factors absolutely do play a role.