I am not hard of thinking or reasoning... and at no point did I say people could change sex. I said gender. What I am is someone who disagrees with you - there is a difference. I do not share your opinion.
I believe people can make a choice to identify as a gender other than that with which they were born. This is not an easy choice to make. I believe children (or young adults) need support rather than being ostracised. Personally I would rather a teen working out who they are is given a chance to experience life as the other gender if they think that is who they are. My positive experiences of both scouts and guides leads be to believe that a trans boy who believes he should have been born a girl would be well supported. No one would force children to share tents who didn't want to - even same sex children as that way chaos lies.
A girl is a child/teen who lives life as a female, who uses female pronouns. A woman is an adult who lives life as a female. It is not difficult. By living life I mean they wake up, walk, talk, eat, go to sleep female - not that they pick and chose on a daily basis. (although I am not a fan of cis - I do not choose to be identified as a cis female - just female).
I don't agree with the race analogy at all. I can choose a religion. I can choose to live in the manner of a different race - food, culture, etc.I can change nationality and identify with another. I am British. I live in Switzerland. My son, despite having a British passport identifies as Swiss. Yes, I cannot change my skin colour but race is more than just skin colour. Re: diversity quotas, awards etc, it depends on the terms of each individual award etc... Race and gender are not comparable.
(yes you are right it is just scouts I was a scout and I am female no idea where the stray boy came from)