We've got a whole new world opening up to kids. They have to wrap their minds around issues that adults are having trouble with. How can they be expected to make a reasoned knowledgeable decision about their own sexuality with so much peer pressure, adult expectations and societal influences?
Personally I think I would go with "Be who you want to be, but honor the body you are born with even if it's not perfect." In a nutshell, that's my best effort. But tell me about kids that are questioning their identity. I thought for about a year in adolescence that I might be gay...I'm not, but imagine if I had gone through the coming out process, and then had to crawl back in! Mortifying! How do parents and school counselors help kids get though?
Regarding transgender folk, If a kid decides to take hormones, can they change their mind in a year, and have everything go back to normal? Will puberty take place, just delayed for a year? If they put off hormone therapy until they get through adolescence, what are the disadvantages? I hate to have a kid make a life changing decision at 12-13 years old, and have no way to change their minds.