Your OP was unclear as to what you are proposing and how you would implement it:
It should of been clear to those that applied proper comprehension skills.
For your pleasure though, I will reiterate points that have already been made.
1. Are you advocating for individual or group unisex bathrooms?
Group unisex bathrooms, obviously.
2. Why "should" all men and women use the same bathroom?
Same sex bathrooms are unnecessary, inefficient, and outdated
3. Would you make this a legal requirement? What penalties would you assess for noncompliance?
No laws and no penalties.
4. Would you require retrofitting existing bathrooms or just for new construction? Who would pay for it?
Independent individuals that have property with a bathroom in it.
5. Why are you opposed to allowing people to choose whether or not they want to use a unisex bathroom?
This is a loaded question.
I believe in choice.
6. Are you going to answer these questions or resort to pseudo-intellectual word games?
I am going to watch the flag of idiocy fly.
TRANSLATION: You would like to see all people in the same bathrooms, but don't have the balls to suggest it be mandatory.
P.S. When did you have your surgery?