I definitely agree with most of what you're saying, Soundslike, especially when it comes to my observation of "hipster" behavior in person. But I do think that for the most part, even the hipsters who get ridiculously caught up in their "look", are, as you say, just having fun. I think there's a lot of strange resentment toward people who are willing to take their tastes to an extreme now--it seems that post-grunge, this sort of thing is seen as decadent. But then, at the same time, some of the same people who complain about hipsters and their maximalism will mourn the loss of our abillity to go so far over-the-top as we did in the glam, post-glam, new wave days. I get frustrated with that, because you can't have it both ways: either people should be able to be fey and ridiculous in the service of making an aesthetic "statement" with their image, or they shouldn't. If you think they shouldn't, then how do you expect music (as something heavily entangled in identity politics, everyday cultural semiotics, and iconography) to move forward?
I think that's why it's best to leave any "perjorative" connotations out of my use of hipster, because it just sounds like sour grapes to me. We're all just a slice out of the consumer pie, when you start looking closely at how we live, how we consume music, how we dress, etc.