but they don't have the right to require everyone else to play along.
See, that's probably where you are going to be wrong, eventually. Not "everyone", per se, but you can pretty much count on it being enforced in workplaces. Trans folk have as much a right as anyone else to a nonhostile work environment, and the offending parties aren't going to successfully make the argument that them having to say "She" instead of "he" somehow represents hostility toward themselves. Schools, too. But no, nobody is going to arrest you for it, or in your home, and not in church.