To people who've read all of this: Is someone other than Itsuki "crossdressing" here? If not, I'd like to remove the tag.
As for whether it's to be tagged "shoujo-ai" or not... ugh...
So—I'm on the "well, duh, so long as one protagonist who identifies as a girl, likes another who they recognize is a girl, it's shoujo-ai (or yuri)" side of things—but when we do that it seems to start a tag battle with (mostly) straight guys who throw hissy-fits about things not being what they're expecting...
At some point there's going to have to be an official policy on whether expressed gender-identity is what counts for tags, but I don't want to start that discussion with the admins if it hasn't been already because they haven't struck me as terribly sensitive about gender issues (though that's just an impression).
@930310:
I think you're overstating things a bit to make your point, to say that sex has
nothing to do with gender (using your definitions of both, that is—those words are historically synonyms regardless of any current developing usage, so it's a bit complicated...) is patently absurd.
By crude analogy, that'd be like saying sex (the other kind) and love have nothing to do with each other—sure, they can exist independently, but nonetheless our overall concept of one of them would be quite different, if not for the other.