"I suppose all responses to crime would be considered vigilante since you're implying the only legitimate (non-vigilante) form of violence is that of the state."

I am sure I didn't imply "only".

" In a voluntary anarchist society you could still have something like a police force. Everyone could opt to pay for salaries, equipment, etc. and give a select few the responsibility to answer calls of distress/punish people who violate the rights of others."
So in other words, protection agencies would arise?

" But their authority would be recognized only by the people who take part in the voluntary system, so you get away from the 'taxation is theft' problem."

So those who don't pay the police can't be arrested by them and can do whatever they want to them and their property?

"But yeah, if you're out in the Mad Max desert and some dickhead steals your ride, its your responsibility to solve that problem...or more to the point it was your responsibility to prevent this in some way- maybe settle in a place with the aforementioned sorta security force or at least arm yourself in order to protect your property/deincentivize crimes against you."

Uh huh, and what if I think one dickhead did it so I go shoot him in the face but then it turns out to be a different dickhead? how do we resolve that? I thought we were trying to get away from violence?

that's the whole problem right, this anarchist fantasy takes place in a mad max realm that does not really exist.

There are plenty of examples of what happens when the government is not fulfilling its basic roles. The voluntary police forces in fact arise and we call them gangs and the mafia. We call that protection "extortion".