But somehow the way it's done on LotS feels, I don't know, balanced or something; it both laughs at us and itself and at the same time doesn't ridicule itself--or us--for enjoying.

Yes! The show is poking fun (at itself, at the genre, at the audience), but it's done out of fondness and not contempt.

the repeating fannish social structures that grow up around fic have started feeling stale to me.

Oh, now that's an interesting observation! I have things that I've grown really tired of about fic (mostly about how everything seems to revolve around pairings, thus creating pretty rigid categories that I think might warp what gets written and what doesn't), but I'd be curious to know what you are thinking of. If you want to elaborate, that is!

but hey, they also serve who only show up and squee!

This is true! I need to remind myself of that and get out there squeeing some more. Because there are a lot of things that deserve squee!