What should be in it? I think of it as something less than an abstract principle ("everyone has the right to undertake any transaction that does not involve fraud") and something more than a policy proposal. My thinking is that if something were debated and passed through the arduous Constitutional process, it might stick for a while.
Of course, folks on the left could come up with their sort of rights: a right to free health care, a right for everyone to go to college, a right to able to fly by flapping your arms, etc. Fine, let them try to pass those rights.
I am thinking of a bill of rights that would free us from government credentialing systems, unwanted government services, and government price controls. So, some possibilities:
1. A right for a landlord and tenant to agree to a price without government interference.
2. A right for a consumer and a provider to agree on the qualifications of the provider to offer the serviced without government interference.
3. A right for a worker and an employer to agree on wages and benefits without government interference.
4. A right for people to opt out of government programs wherever feasible. It is not feasible to opt out of national defense or the court system, but it is feasible to opt out of government schools and government retirement systems. Governments at all levels must establish reasonable terms that allow people to opt out.