Property rights are not initiation of aggression. The aggressor is the one who violates the rights of the property owner. If you're going to get that confused, the discussion will go in circles. But please realize that it will also be extremely boring: the oldest error in the book is to confuse defense of self and property with initiation of aggression. It isn't novel, interesting or amusing. It serves no discursive purpose, and it's already been done to death.
You are sidestepping the issue. If it helps you think more easily about it, you can view the gov as the property owner in your dad's analogy. The British colonists pushed the Indians out mostly by force of arms. The founding fathers pushed the British gov out by force of arms and established their own gov. Since then, we have had a mostly unbroken chain of switch of ownership up to now. If you want to push the fedgov out, then pick up a rifle and good luck.
Sigh. VOLUNTARILY. I can hire any security agency, or NO security agency, as it pleases me. There is no parallel between subscription to security services and taxation.
Again sidestepping and going into impracticality. In your society, you can say "Leave me the hell alone and I will defend myself." But in practice, others will be unable to defend themselves, and they will either be victimized or will pay for protection, to an organization that will ultimately become the new gov. Then the new gov will come aknocking on your door, to push you out or tax you. Then you fight them and you lose. So, at best, the system is unstable.
Don't take my word on it. Read some history. This stuff happened to free grazers vs ranchers, and farmers vs the railroads, in a situation that was essentially gov-less. Your type did not fare well at all. Be honest enough to draw to respective conclusions.
For many people, it probably would: your security is partly subsidized by funds stolen from others. Paying the full cost of your own security would of course cost more than forcing others at gunpoint to pay it for you. Obviously. On the other hand, you can opt out completely if you have nothing worth stealing, or you can buy high-deductible services, or subcontract emergency-only services through an insurance provider, so you'll have many more options than today. You can't actually say whether a given person will spend more for security or less.
Even if you live in a shack in the mountains, eventually there will be people wanting to kick you out or limit you in some way. And there will be those wanting to mess with you just for the heck of it. Even if you are Charles Bronson, at best you'd have to be constantly on the run, hounded like an animal. Even if you are naked in the bush drinking mud water and eating garbage, you'd be in somebody's way eventually.
Initiation of force is initiation of force. Whether you're forcibly seizing 25% of my income, imprisoning me in a cage, or forcibly sodomizing me, you're initiating aggression against my person or property without my consent. All initiation of aggression is the moral equivalent of rape.
By any definition, some form of aggression will always be present, so long as two individuals have conflicting interests. A well-run society is one that has ways to resolve the conflict in efficient ways with minimal damage and as close to the principle of equivalence as possible. That is why the most successful societies are the ones with good, enforced laws.
(This is a good time to point out again: since you have already eschewed moral considerations, the conversation is necessarily meaningless to you. But apparently you haven't quite realized it yet.)
You can keep throwing that in my face, but you are only trying to sidestep the practical problems associated with your system. I do not offer moral judgement, just the bare facts that there are people out there that don't share your morality and thus will conflict with you. Your system has to have ways to deal with them, or it will not work. You have offered no practicable solutions to that.
Do you always blame the victim? I hope none of your loved ones is ever the victim of violence. Your handling of their case will suck, and your relationship will probably be adversely affected.
More non-sequitur. Pointing out that a defenseless party will be victimized is by no means blaming them. It is a neutral statementof fact of nature. What you read in it is your subjective business.
In any case, it seems like you are switching from unsubstantiated preaching to morality attacks, so it looks like the semi-rational discussion is over at this point.