A GRC should go alongside the original BC and states that this individual lives as a member of the opppsite sex
No, because this presupposes that there's a way to live "as a member of the opposite sex" without having that biology.
Wearing clothes, painting your face, styling your hair as you see fit - these are not woman-things, they are human things.
Living as a woman means menstruating / worrying that you're not menstruating / dreading that you're going to menstruate / having investigations into why you're not menstruating / thanking your lucky stars that you no longer menstruate. The female biological reference points are what allow our experiences to be described as "living as women" rather than "living as humans".
No. That [people realising gender roles are oppressive to all] doesn’t address sex dysphoria.
It does if you're not wilfully blind to the fact that strictly enforced sex-roles and sex-role stereotypes are major factors in sex dysmorphia.
Go and read the accounts of the old-school transsexuals, if you don't believe me. Read about their childhoods. There's a common theme. Rigid and often violent enforcement of masculinity standards; rampant homophobia; corrective physical and sometimes sexual abuse crop up again and again.
There might not be much that can be done for those who have intractable sex dysmorphia right now, but we could sure as hell be doing more to reduce the number of kids laying the foundations for it right now.