Here’s two cents in a few words:
No, there is no pregnancy
Yes, there are people who have it inside themselves to feel like they are the other gender and they should not be discriminated against (employment, rental, military, etc.) but see below comment on sports
I couldn’t care less about rest rooms, locker rooms, etc. Much ado about nothing. They are way less of a risk than priests, scout leaders, etc. have been over the years
They should wait until they are adults to transition physically. Sorry, I do not believe children, even teenagers always know who they are yet (I know transition doctors disagree)
They should not play in competitive sports (of their new gender) after transitioning, unfair.