For the most part I agree with you--all three... genres seems like the wrong term to me, since I tend to think of that as mystery or fantasy or historical fiction, non-fiction, porn, etc, rather than how the bits fit together. All three configurations can be very, very good, or they can be very, very bad. Empowering, or exploitative. And most of the stories written of any of them will just be crap.

However, I felt like you missed the biggest pitfalls of femmeslash: objectification. I would say that, at it's worst, femmeslash erases real lesbians and creates a sort of category of straight or bisexual women who preform lesbian acts for the titillation of the viewer/reader, normally presumed to be male. Obviously, lesbians (gays) dying as a result of their forbidden love is a very problematic trope, but I would say that lesbianism for male consumption is alive and well in fandom, and at least as bad.

I also think that it's a little troubling to say that het is at it's best when it's a deconstruction. Yes, yes, I know; poor little heterosexuals without all their representation--BUT. I would say that representations of equal partnerships in het relationships are far from well represented. Het fic can also be a way to celebrate and explore that, as well as to deconstruct the problematic nature of traditional het narratives.

So, like I said, I agree with most of this, but those are two things I'd add to the list.