I'll keep those terminological points in mind. Shortness and brevity is a virtue for a word, but 'trans' is shorter than 'trannie' or 'tranny' so that would work while apparently not being offensive.

Hey, is that a Japanese cross-sex-reincarnation compersion song? Awesome.

Well, that video is something alright... Vocaloid is actually a bit relevant to discussions of moderation/censorship - because there's essentially no filter on the music/video host NND and making Vocaloid songs or videos is open to anyone who wants to, you get plenty of poor quality or offensive videos (sexism, homosexual stereotyping, ethnocentrism) but you also get all sorts of bafflingly idiosyncratic or strange or unique gems. (To give a memorable example, a few days ago I was watching a pair of BDSM-themed songs pairing Miku as top and Luka as bottom, each song giving one's perspective, with the usual cute drawings and short animation. Not one's usual fare.)