My reading of all of that is that "regulated" would have absolutely been understood as meaning "subject to regulation by proper authority" at the time of the Co

My reading of all of that is that "regulated" would have absolutely been understood as meaning "subject to regulation by proper authority" at the time of the Constitution's drafting. The Framers would have considered the states to be the proper authority, and thus the Second Amendment prohibits Congress from interfering in the states' ability to organize militias.