MechaPilot
Explorer
Gender identity is one of the deepest identities of most humans. Integrity requires most characters to be true to their gender identity.
Transgendered humans exist because they cant deny or escape their gender identity.
Gender is absolutely integral to a character.
I am aware of gender vs gender identity, the importance of gender identity to a person, and the difficulties when they don't match up, but don't throw up gender identity as a smokescreen: in most literature and films gender and gender identity match up.