I disagree with your last point. There's a reason that "gay" is used for (male) homosexual. It began as a euphamism for a reason. It's true that "dour" often follows from "lesbian" but not always. I'm not willing to make generalizations on this point. I'm only going to say that it holds in Rosie's case.
Every gay dude I have ever known, about 5 different fellows, was really sweet. But the few lesbians I have come in contact with have been really bitter women. And I don't understand the concept of hating men and yet wanting to look like a man. It doesn't make sense.