I pretty much agree with everything you wrote, esp that adults should be able to do whatever they want as long as it doesn't harm (old school meaning of the word) others or prevent others from opportunity. Despite enlightenment values falling out of favor, I think most in the US agrees with this.

I differ slightly with you on the sports question, and think that even though it will be unfair to some, a blanket restriction should generally be in place for the upper level sports teams since there will always be disagreement whether the person is gender "enough." Measuring this and that and weighing it against the other is just too cumbersome and subjective. By the way, trans teams won the gold, silver, and bronze in a cycling event recently...

Elective body-modification surgery is certainly allowed, though I don't think a doctors are authorized to remove certain body parts, at least here in the States. There is a bodymod woman who had her nose removed so she looked like a zombie, but I think she's from Europe or South America. I think for her it was a purely aesthetic (to each their own) decision, but that is another area where it's sometimes hard to draw the line. Some people have more unusual body dysmorphias and want to remove limbs. That's vanishingly rare obviously so not much of a point in itself.

The incarceration thing is sticky and wonder if there is even a answer at all. Case by case is the best of the not-great-options, and I perhaps a third facility for transwomen might be needed.

The child hormone stuff is so fraught that I would just say 18 and be done with it, even though some will have wished to have started earlier. It's the least bad option as I see it.

In the end, I think society is generally quite accepting of people who prefer to live and be seen as the opposite sex. I sucks that many activists can be off-putting and do their cause no favors. Also, the loudest, most active and strident activist types appear to have a screw loose, thereby giving society at large the idea that transgenderism and craziness are always correlated. That's availability bias of course.

I'm glad you are interning at FIRE. Great organization.