What is the ruling on a woman taking off her clothes outside her home, and does removing the hijab for ablution count as part of that? And what is the ruling on relieving oneself in restaurants and public places when necessary?

The prohibition against a woman removing her clothes outside her husband's home is mentioned in an authentic Hadith. Scholars have interpreted this as a metaphor for her exposing herself to non-mahram men. Therefore, there is no objection to a woman removing her clothes in a place where non-mahram men cannot see her. The same applies to relieving oneself and performing ablution in designated areas, as long as it does not lead to her exposure in front of non-mahram men, while also being mindful of the presence of surveillance cameras in some public places.