And, once again, the feds in Article V provide a means to alter powers by amending the Constitution. And did not limit amendments to limiting federal powers. So your argument falls apart both on two fronts - by the plain text of Article V, and by the ratification of the Constitution itself, which was an increase of federal powers at the expense of the states under the Articles of Confederation.
Yes they do. However as #45 points out, one can't reasonably state the Constitution would have been amended for such issues as the document wouldn't apply to the states (for the most part) in the first place. From the understanding of the Framers, why would you amend a federal document to change a state law? That is in effect what you are doing. You wouldn't. One would first have to make the Constitution apply to the states (done through incorporation by activist judges from 1898-1937).
We're talking original intent here, not after the document was made null and void. Frankly, considering our current form of government, the Constitution of these United States is not much more than a worthless piece of paper. Historical value yes, but as for applying to the government? Forget it. Forget judges ignoring it, politicians ignore it every day.