> The proposition is not to remove the framework, but to de-monopolize it.
To demonopolize it is to remove it. The monopoly is the essence of the framework.
> We currently have a government framework of law, but nothing (except people not realizing it's even possible) prevents us from having multiple frameworks, each operating on its own client base (even when those clients physically live on the same territory) and negotiating with each other when disputes between clients of two different agencies arise.
This kind of patron/client system is not novel, and most people do, in fact, recognize that it is possible.
> The major difference in this situation would be that clients of such firms would voluntarily pay money to be protected by them.
Unless there is some supervisory entity that does have a monopoly enforcing it (in which case, this remains a monopoly system with low-level enforcement farmed out, not a demonopolized system), voluntariness seems, well, dubious. You've just invented a system competing warlords (well, invented is too strong a term, its the basic model of primitive feudalism.)