Will answer to several posters at once, but forgive me if i don't answer in too much detail as it may be too identifying.
No my son is not autistic.
No there is no history of abuse. ( is there a link?!)
Yes he has looked into all the pros & cons & we have discussed them at length together & with his specialists.
No he is not currently dating as far as I'm aware, lets face it any mother of a young man is usually the last to know isn't she?!! 
He'll tell me as & when I need to know.
mozzie if you read some of my previous answers they'll answer some of yours 
My sons rights in no way invalidate his sisters, they both have human rights & respect and support each other.
thegolden of course I wish he could have been happier with his birth gender, no mother/parent would choose that path for their child. However that was never going to be, he was always a boy underneath I just didn't know it then, I do now .
Morning NetofLemons no we went NHS the whole way, there was no option for us to go private. He had superb service, very caring, thorough & compassionate. My only concern was (& is) is the lack of counselling available to us as a family and to him on his own.
We got funding for a brief 10 weeks -10 x 1 hour sessions with our local Relate service who were superb. For months after the funding ended I scraped together enough to pay for the same sessions as it was keeping us all sane.
Sadly then the Local Authority in its wisdom pulled the plug on the total funding so the service closed. We were all devestated as we had built up a good relationship with our counsellor, but we managed to track her down when she set up privately and have carried on seeing her since, individually.
I really feel that with the long waiting lists for gender specialist centres, it puts an intolerable strain on families to the detriment of the mental health of all as they struggle through.
Early intervention with talking therapies has been proven time and again in all fields of child mental health to be very useful, yet along with other MH services in general, budget cuts are reducing this valuable service.