I'd add an Amendment that requires all rules that have the force of Law, to have been passed as Laws are. Put another way, only Congress can pass laws; bureaucracies can not, nor can the President.
Also, adjust Article 7 (?) to reflect that no treaty may overrule the Constitution. As-is, such a treaty can overrule the 1st Amendment's guarantees of freedom of religion and speech, the 2nd Amendment's guarantee of the right to keep and bear arms, etc.