Does an NCO, with whom I have no work relationship, have authority over me when I'm out of uniform, off post, and off duty?

No really an issue, for myself, but their is an NCO in the area which I live always calling soldiers out for being out of uniform, went walking to their residence, when he himself does the same, so respectfully of course I want to correct him for doing the same. I spoke with my first line, she told me as an Nco off post her authority doesn't go as far, (of course I get being in uniform, while in the uniform, I just dont like him calling fellow soldiers out when I see him doing the same, I wanted to verify, the whole nco authority off post deal before I get myself in trouble)

SPC (Join to see) - I'd choose my battles and probably skip this one. But I'll defer to people still Soldiering for a more specific and accurate answer.

SPC (Join to see) - Soldiers are Soldiers 24/7. We are expected to act accordingly 24/7 on or off base. If the NCO is in civilians and sees a Soldier out of uniform (for example, wearing OCP pants, croc shoes, and a civilian t-shirt standing outside smoking) then they have every right based on General Military Authority to correct the actions. In fact, based on General Military Authority, you also have that right and obligation (albeit very tactfully and respectfully) to call them out on their infractions. And to me, at least IMHO, the answer of your first line sounds like a cop-out.

MSG (Join to see) very helpful thank you Ssg.