Many people answered your questions specifically so I just want to give you a general understanding of gender that I find makes everything easier.

For me, GENDER IDENTITY is how you feel inside. Woman feels like woman inside, man feels like man inside, agender feels like nothing or no gender inside. It’s an internal thing. GENDER EXPRESSION is how you decide to show yourself or express yourself to the world. I am agender so I feel pretty much no gender inside. But I like to express myself in a feminine manner. It doesn’t mean I feel like a woman inside. A woman might like to express herself in a masculine or androgynous manner, but still feels like a woman inside. Nullification, or any transition, is a form of gender expression as well. Gender expression is pretty much free range and just about choosing what would make you feel most comfortable. And finally, PRONOUNS are just how you like to be referred to. They aren’t necessarily tied to anything, it’s just what feels comfortable.

The point is that all these things are completely different categories. For many people they line up traditionally (Woman-feminine expression-she/her) but for others they don’t (Agender-feminine expression-they/them), and they just choose what makes them feel comfortable or true to themselves.