See, I don't really see fantasia as being the support I'm talking about, as I really doubt SE put it in with trans people in mind, like.. Outside of trans folks who start playing the game with people they're closeted to irl or maybe they come to terms with it later in life while, I'd figure most trans folks would just play as the gender they identify with. I figure fantasia (Due to the fact that it basically just lets you recreate your character) is there for anyone who just wants to drop 10$ for a change for fun. Not to mention the whole ordeal of fantasia being dubiously canon, we literally get them from the mail mysteriously (As our characters have no concept of a "Mog station"). Like.. I want to be considered like any other woman myself, but I don't want to shove the whole transgender thing in a box and kick it in the closet, in a similar way as a pansexual person I might end up in a heterosexual relationship for the rest of my life, but I don't want to hide the fact that I am pansexual. Like getting an exact consensus on this whole ordeal is nigh impossible, so I could say many (if not most) of us trans women, "post" transition or not, want to be seen as trans women, though that isn't to say your claim doesn't have a level of validity to it. Now.. I'd have to question why you associate being in the midst of transition as being "non-binary", as I don't really think there's an end to transitioning (Especially not currently) nor do you have to even touch hormones to be considered your identity of choice (As plenty of cis women have variable levels of hormones, and I know plenty of non-binary and binary trans people that either don't want hormones or can't access them). Like.. I'd really argue "trans people are forced to express and be seen as non-binary during their transition." is due in part to the way cis people (And some trans people) interpret gender identity, like do we also look at very masculine women (Such as ones with natural high testosterone levels) as non-binary as well? Like, I personally don't associate gender identity with physical appearance, so I really don't get why it has to be that way.
I mean, I'm glad fantasia fits your idea of an "ideal trans person fantasy", but fantasia certainly doesn't fit mine. Like.. Outside of the dubiousness canon-ness of fantasia or even if it is 100% canon as something even available to regular people of Eorzea, I just don't jive with the whole "You're suddenly 100% identical to a cis woman!" idea, I feel like it falsifies who I am and my struggles to have this magical solution to the issue, kinda akin to like "Taking a magical potion and waking up straight!" or something imho. I appreciate this quantitative/qualitative idea that my character can be transgender like I am, go through a generic transition like I am, et cetera.. Like.. Stuff that allows for the stereotypical traits of the opposite sex (And I'm only using the terminology of "opposite sex" due to how the game is presented) on the sex of your choice would my "ideal trans person fantasy". Stuff like "7'3 Au Ra girl with stereotypical male scale pattern and a more masculine face (IE scale chin crests and all)", "Roegadyn woman with a bit of a more square body", or just like even "Miqo'te girl that's 5'8 and has a face that's kind of masculine". It doesn't have to necessarily equate to "This is the trans option." (As a lot of cis women do have plenty of stereotypical masculine features), but it does allow for me to visualize my character as a trans person much easier. Pronoun choices and having every piece of gear being unisex would also be a pretty viable way for helping this issue as well imho. Like.. I value that I'm a woman, but I also value that I'm a trans woman. I'm not cis, nor do I really want to be as I'm prideful of who I am.
I really don't qualify the boss of T9 as a trans dude to be honest, after rewatching the cutscene all they say in regards to it is like "Huh, this is odd." but they don't seem to express anything akin to dysphoria or any particular association with being a guy either, just a "Huh this is odd, but whatever! Anyways blah blah plot spoilers about who the boss is." (Like if we're going to talk about "If I had to associate them with a transgender identity" I'd go with non-binary or agender to be honest).. And even then, I don't really consider something akin basically akin to "Mind swap" as being transgender or being proper transgender representation either. Also I'd be really interested in a citation on that claim, because off the top of my head I can think of some notable Japanese trans women, but I really can't think of any notable Japanese trans men though.. While that doesn't necessarily refute the claim you make, I do find it hard to believe that it somehow trans men are more common yet less notable within the media.
Being non-binary is being trans, but you don't have to be non-binary if you identify as a binary trans identity, like you still transition (Or not really if it how you feel about you and your gender doesn't fit the idea of transitioning) to fit your personal idea of you and your gender as any of the plethora of non-binary identities.
It's not, but like basically every bit of the post moogle quests aren't any of our business really (Like the quests in the line are quite literally "Solve/follow X while they solve X's personal problems" most of the time), they're events we observe and hey, maybe we end up being someone's confidant in one of those quests with regards to their gender identity . Plus, it's kind of hard to have any trans representation within the game whenever that sort of logic is used, like we don't really need to know anything about the NPCs but we get them.. It's kinda like saying "This game has perfect pan/bisexual representation!" by just assuming any character we meet is just showing heterosexual interests at this current moment but is actually bisexual or pansexual, like it's the different between Hauchefant (And a Miqo'te woman in the Hidden Springs) and just doing what you're talking about because we don't want to pry into fictional character's personal lives.
Like currently, considering the whole "Manderville in a dress" "joke" and the "joke" the NA translators slide in with involving certain NPC and Alphinaud's feminine appearance, I really don't think SE or the NA translators have trans people in mind with this game.