Libertarianism: everyone is a rational actor, always. We shot all the people with mental illnesses.
Not so. Mentally ill people already take medication, and those who commit crime are treated like most any other person; this does not change, no matter what system you live under. Though Libertarians may generally be rational, they should not assume all people of the world will always be rational. Are you one of those irrational people? If not, don't worry about them; they already figured out how to get by now, they'll figure it out any other way. If you are, you should already know how you're getting along now.
The only way I could see this possibly working is if there was a standard rules agreement and people had to list where there rules deviated from that.
We already have that; just list everything you don't like to happen to you, and then don't do that to other people. Ta-da; it may seem surprising, but most people generally don't like the same things. If you want a really simplified version of this:
1. Don't fuck with people.
2. Don't get fucked.
You are absolutely correct @Mike Christ.
Although many of us disagree on details - the vast majority agree on the major issues. And that gives me hope.
Now if we can just somehow (and please, dear God don't anyone suggest voting or protesting) get rid of the dangerous criminals in congress... people who are really just bought/paid for mafia type "capos" working for the corporations... and then maybe, just maybe... we can begin to restore our democracy.