I'm new to the idea of anarchy, so bear with me as I work through some of the doubts and questions.
I REALLY want to believe that people are inherently good and want to do the right thing. However, my idea of the "right thing" and someone else's can be completely different. I believe vaccinations should be mandatory, but others believe believe they're not necessary. I don't think abortion is acceptable, but others do. I don't know if I reconcile my beliefs to being tolerant of everyone else's beliefs. Which is why I have a hard time believing everyone is willing to work together for a common good- my own selfish nature wants everything to be done MY way or at least have a way to petition for my way to be the universal "right" way. When people do things that are punishable(murder, rape, steal)- I want them to be punished. Who decides what's a punishable offense and what punishment the offense deserves? Who carries out the punishment?
Not everyone is inherently good. A certain percentage of the population is psychopathic and we should take steps to protect ourselves and our loved ones from them.
I wanted to include more in my post, but it already has a lot of content. One of my favorite videos on some of the topics you described is right here:
The short answer is, we can't "force" anyone to do anything. This is not how adults behave in 95%+ (sorry, that's a made up number) of our human interactions. No one tells you what to eat, what to wear, where to live, what car to buy, what house to rent or buy, who to marry, who to associate with, etc. The "no rulers" concept of anarchy and voluntaryism is how we already interact.
When it comes to the NAP, it's about crimes with actual victims. Vaccinations is an interesting one (as is second-hand smoke) because there are victims and some may be aggressing against others, even if they don't realize it. Abortion is also challenging because people have wildly different views on the sanctity of life and if a few cells should have equal right to well-being as a fully-grown adult while others argue some arbitrary moment of birth somehow gives new rights to a fully-functioning living being who was previously just as alive, but inhabiting the space of another individual. Drawing hard lines is very difficult in worlds of grey which is all the more reason (IMO), we should tread carefully and humbly. Good ideas don't require force. If we can't persuade others peacefully, we can disassociate with them or make a stronger case for why they are aggressing against others, creating victims who justifiably need protection.
The ideas of voluntary interaction do reveal much of the selfish, primitive, authoritarian thinking I mentioned in my post. We all have it, but I also believe we can move beyond it. Universal "rights" are very hard to argue for, but I think the NAP comes close, so that's a good place to start when thinking about this stuff.
Thanks for commenting!