I think you're missing my point, which has to do not with the desirability of entering into such an agreement, but rather with how to enforce such an agreement in the absence of any sort of state.
You wont be able to enforce every arbitrary agreement. The constitutional courts will only rule on limited matters such as physical aggressions.
And (for example) for Oracle to enforce non-compete, It will have to come in agreement with big corps such as Google/Amazon/Facebook/etc. This will work for most cases. But former-employee of Oracle will be able to work at Joyent.
In conclusion, You have to get help from others to enforce an agreement not enforced by Govt.
Also note, constitution ~= what everyone consents on. That is, 1. It will be short & sweet. Everyone will be able to understand it. No suprises. 2. It will never have surveillance measures.
