Some states have this. In Texas for example there is a statewide standard residential lease contract. When you rent property in Texas you know what you're getting into.
Ive been trying to think of an effective way of regulating these sorts of contacts through legislation, and what you're describing seems like the simplest route. Simply have the public draft the standard contractual templates on behalf of consumers/employees/tenants that companies/employers/landlords are constrained to use.
Unless there's any reason to think the corps would have any less influence on that than they have on the laws that allow them to get people to waive their rights to sue - and why would they? - that sounds like a great way to prevent customers from escaping abusive conditions.
As a good example, the aforementioned Texas agreement seems to have a clause that states that the landlord can enter the property at any time without previous notice. Preventing the landlord from giving up that right is not a good thing.
Good point. I'm not even really one to turn to legislative remedies. It's difficult to imagine many practical ways to match the vast legal resources of these established interests against individuals.