This is Fiendly Notes here, with your host, Zakon!
1 - Transgender people are still transgender, even if they choose not to get the hormone treatments or the surgeries. It is none of your business what they are doing with their bodies, and it is your responsibility to use the correct pronouns for them.
2 - If someone gives you multiple pronouns to use for them(ex. He/him/they/them), you should use all of the pronouns listed, unless they make it clear that you only have to use one set.
3 - Neopronoun users are valid. Use the pronouns they give you.
4 - They/Them pronouns are not strictly plural. If you truly believe that 'they' is only plural, then you also should also only use the word 'you' to refer to multiple people. Thou art only thou from now on, buddy. Or you can accept that language changes.
This has been Fiendly Notes! Join us next time here in Hell's VIP lounge, home of the girls, gays, and theys, for an exclusive meeting with the new Lord of Hell himself, Lil Nas X!