So when we own our identities through not having a definition of the words, what's to prevent people from saying in their heads "oh, that one is just crazy and full of shit" and continuing to treat us the way they always did?

I'm all for being hardcore, owning our identities and all. And I do regret pandering to my dad's unfortunate inclination to challenge anything he disagrees with by providing an explanation to begin with. But what credibility do we have in claiming an identity if that identity doesn't actually have a meaning? Say I identify as a "Vistarole". What does that mean? What am I saying with that word? And if someone tells me that what I just said is idiotic, how would I address that when Vistarole has no definition?

So much of what you've been saying has centered the experience of those of us who can afford to physically transition. It might not be intentional (again, classism is a system, it doesn't have to be malicious), but it's there, and yes, it's classism creeping into the argument.

I mostly did that because I can't operate outside of my own experiences all that effectively. So the examples I use are based around what I know exists and not what I assume exists for folk who aren't me.

Although the example of how we articulate our situation at all (being trans in general) would apply to pretty much any trans person.