How should we treat trans people?
Exactly the same way we treat everyone else.
Like everyone else they can use the appropriate facilities for their sex as determined at conception and observed at birth.
Like everyone else they can enter into heterosexual relationships with members of the opposite sex or homosexual ones with members of their own sex providing they are consensual and involve no deception.
Like everyone else they can hold whatever unsubstantiated beliefs, such as a belief in disembodied gendered souls, and accept that no one else is required to share their unsubstantiated belief.
Like everyone else they can express their beliefs, eg through use of wrong sex pronouns, and accept that others are not required to play along.
Like everyone else they can dress how they like within the bounds of law and company policy if they are employed by another party.
Like everyone else if they struggle with their mental health they should be entitled to appropriate therapy.
No treating them worse than others, no giving them special privileges.