Responding to the point you raise here and in a parallel thread.
I had to read through the entire thread to pick up on where we left off!
When I say that the NAP is foundational, I intend this to be understood in the legal context. (See above where I say “Now, law in any libertarian society would have the NAP at its core.”) If someone were to ask why we should observe the NAP in our relations with others, we would have to say that not to do so would violate the property others have in themselves, which is precisely your point.
You write “To have a consistent logical foundation here, the individual himself or herself must always unilaterally have self-ownership, and does not require anyone else’s permission or consent to assert this. However, this leads to many obvious conundrums described in the thread above.” I agree with you on this point but I don’t think that the boundary conundrums cause us any insuperable problems. Fully adult, articulate, independent human beings are unequivocally self-owners; two year old, babbling, dependent human beings are not.
That we cannot draw a sharp dividing line between the two does not call either clear example into question. That’s why I spent some time laying out the sorites. Night is night, and day is day, but in between there is evening, gloaming and dawn.
Thank you for your prayers.