I’ve seen DS9 multiple times, but I have no clue what you’re talking about on some of these. Please enlighten me.
A trans lesbian officer
Are you talking about Jadzia/Ezri-Dax? If so, neither are trans. The parasite, Dax, in them has no gender but can go to different hosts that have genders.
A gay interspecies couple
Are you talking about Odo and Kira? While Odo doesn’t have gender, I wouldn’t call it a gay interspecies couple. That’s kind of a stretch.
Edited for format
Sup