> If they do, they have interest in not passing and constantly outing themselves to demonstrate their minority status, because this is what they think makes their voice 'valid'.
This is a bit of an outdated view on being "trans". I'll elaborate a bit because this old view on transness I think is the main difference in our views.
As background, I assume we'll both agree that gender is (in western society anyway) stereotypically expressed as a binary: masculine and feminine. The extent and degree of this binary has shifted over time. At one point women wearing pants was unacceptable.
The historical view of transness was that people who are trans wanted to present as the other part of the binary. "I want to be seen as a man instead of a woman". This raises a question: why? The answer follows: "Because I feel like I should be a woman."
If you stop at the first question, your view of trans identities make sense: a trans identity is only valid if it fits snuggly into the existing gender binary. You are a biological male who identifies as a women, or a biological female who identifies as a man. And while both of those work under the second framing, gender nonconforming identities, which don't feel like they should be a woman, but instead feel like they shouldn't be a man (or a woman). I'll note that I'm intentionally simplifying here which has the consequence of erasing some identities like gender-fluidity. The framing still works for those, but the answers are different.
So "old" trans was about perception, "new" trans is about identity. Passing (or not) doesn't make someone's voice valid. Identity does. If you identify as trans, you are and that identity is valid is really how I'd summarize things. There's the potential for abuse of this, but in practice it doesn't happen.
So I reject the notion that one need to be visibly non-passing to be valid in any circle. This I think also addresses much of your second paragraph: there are many people who choose to identify as trans even though they are passing or mostly passing, if only because the shared experience is useful to identify. And they may do so only in certain circles (e.g. Be "out" only in queer circles where they feel more free to discuss their trans experiences).
> many sexually deviant
I'd be careful conflating sexual deviancy with LGBT identities for two reasons. First, "sexual deviancy" has historically been used as a pejorative for LGBT people in the US, and I assume elsewhere. And second, it's not particularly relevant. In psychology, "sexual deviancy" refers to paraphilias or kinks, which are explicitly sexual in nature. But a trans or gay person could be totally asexual. Even still, they could be romantically attracted to same sex people or have some gender dysphoria. Neither implies anything about the act of sex itself.