You're missing the point. Paying service fees is never taxation because the result of not paying for a service is denying that service, while the result of not paying taxes is forceful alienation of property and possibly imprisonment. I am yet to hear of a private company who threatened its customers with all that if they cancel their subscription. If this happens in the free market with the said protection agency, my point is that it will be called extortion and recognized for what it is. That's important because the threshold of compliance in people lowers when they recognize they are being robbed.
> Prices are set to what the market will pay, in this case it's as close to revolt as the business can get away with.
I don't understand this point. What prevents a competitor (say, a big investor) from entering the market and establishing another big protection firm with lower prices and better service? If you say "they all will form a cartel" then I will point out that cartels are always very unstable and someone deserts or another outsider disrupts the market, historically this has been true.
> I would also like to point out that I don't disagree with your assertion that their are negatives with a government controlled monopoly on law enforcement, I disagree with the idea that a free market system for it would not be subject to worse corruption/abuse.
What could be worse than conducting a theft from people calling it taxation, then be bribed by corporations and using those tax money to serve corporate interests? Simple math: a company bribes an official with $1, the official spends $10 of somebody else's stolen money (so it doesn't cost him anything) for that company interests and that makes the company $100. In the free market, companies at least deal with the money they actually made, so there's no "free" money for them and no one to bribe.