Yes, those seeking power exploit legitimate needs in order to gain that power. However, that does not refute anything I said.
Say that you're living in a completely free society where people generally try to adhere to the NAP as closely as possible. One day, a cold-blooded murder is committed and the victim was unable to successfully defend him or herself. What happens next?
One day, a drunk driver hits another car with a family in it, kills the father and one of the kids, the other kid is paralyzed from the waist down, and the other father (it's a gay family) loses an eye. All video evidence shows that it was the drunk driver's fault, by any objective standard. The drunk driver refuses to voluntarily help the survivors in any way. What happens next?
I love the questions you pose and points you bring up. It really gets me to step back and think critically. At this stage in our evolution I do not think we have the wisdom to be able to answer that. I believe we will gain that wisdom allowing us to handle these situations according to NAP. Anything that we say now would be more theory. This doesn't mean I am copping out, I will offer a theory and accept that it may be flawed.
The victim's rights were infringed upon, and as such has the right to be made whole. Violence and incarceration would not make the victim whole, it would just create another victim. Since these offenders are not voluntarily following with the appropriate actions to make their victims whole, they are still infringing on the victim's rights. The victim(s) are justified in taking action to be made whole and/or compensated. The next step would be to determine what would be proper compensation to the victim.
I think this would be the stage where the two hypotheticals would begin. The local community would be very aware of what had happened and cease trade and communication with and deny right of passage on their property to the offender. This would not be obligated, but in not doing so may be deemed a violation of the victim's rights, thus bringing a potential claim against them. Essentially, the offender would be ostracized and any attempt to leave their property would be considered an act of aggression. Of course, if the offender is totally self sufficient, it could remain at this state for the rest of their life. Total social isolation is crippling to a human and I don't see that happening, but if it did the victim or victim's heirs would still have the right to compensation which would come from the property left behind by the offender.
That was very difficult to write because there are so many possibilities in regards to different courses of action the involved parties could take, but at every point the NAP would need to be adhered to. Anytime that principle is violated, a victim would have a claim to be made whole. By claiming the right to own yourself, you must respect that right in everyone else in order for the first clause to be true.