For appropriation, I can think of many. Of course some people will argue that transgender itself is appropriating the opposite sex (this is especially sensitive for women b/c sexism exists).

The phrase "assigned sex at birth" is appropriated from the intersex community. Transactivists also use intersex people constantly in their arguments even though intersex orgs have pleaded to be left out of these debates because they're really completely separate issues.

Transbians just hit wrong. I feel like unless you're Blaire White, a trans woman is usually pretty clockable, even the ones who claim to be "stealth", and many of them are just blatantly male (like Yaniv or Stefonknee etc). It's hard to not see them as heterosexual men.

I've also seen trans people use the term "femme", which originated as a term lesbians use (butch vs femme). Honestly lesbians don't even really like the terms much but to use them out of context is still appropriation and weird. A lot of "trans femmes" when they mean "trans women" (or if they're mirroring transmasc, then it should be transfem). The other day I saw someone use "assigned femmes" meaning "AFABs". It was an appropriation within an appropriation. Bleah.