Where do you even begin?
1: They’re not telling you anything, THEYRE ASKING you to respect them enough to be nice and take their wishes into account. It doesn’t hit you, no one’s holding a gun to you’re head. It’s the bare minimum we give people who are Cis…why not trans?
2: If you’re not Cis then you’re gender non-binary. Cisgender is merely a scientific term to describe a person who’s gender aligns with their sex. Just like neuro-typical, or Heterosexual. Only a moron would be offended.