That is not true. The AoC was still in existance between those States that did not ratify. "
That's not correct. "On September 13, 1788, the Articles Congress certified that the new Constitution had been ratified. The new government would be inaugurated with eleven of the thirteen. The Articles Congress directed the new government to begin in New York City on the first Wednesday in March,  and on March 4, 1789, the government duly began operations." Source Wikipedia.
That means that the AoC union's own Congress nullified the AoC union and replaced it with the Constitution. (Bear in mind that the AoC Congress unanimously approved sending the Constitution to thestates for ratification as well). There were two remaining states that had not ratified as of yet. are you arguing that those two states comprised a second United States of America still operating under the AoC? That would be silly. So what were the two remaining states classified as if not separate and independent countries? In fact, at least two of the ratifying states (Virginia and another) specifically included language in their ratification enabling them to revert to a separate, soveriegn state should they choose.
"The U.S. Constitution does not say a failure to ratifiy the U.S. Constitution demands the end of the Articles of Confederation and its perpetual Union. "
No it's implied by the fact that the states were sovereign prior to the AoC compact and had only delegated extremely limited powers to the national government, reserving most to themselves. I wouldn't get to hung up on the term "perpetual" since clearly the very same generation that used that term unanimously consented to abolishing the AoC and only rewuired 9 states of the 13 to ratify the Constitution with no intention of compelling the other non-ratifying states to join. Perpetual also means "ongoing", and not necessarily "forever". That would fly in the face of the very independent minded revolutionaries who were so mistrustful of a central government that they didn't give it the power to tax.
"The Constitution did not creat the Union. "
Yes and no. Technically, the Union continued while the Constitution was undergoing ratification. But, yes it did in the sense that it created a new union that only needed 9 of the 13 states to join for it to commence existence. Remember that after this new Union came into being, it did not have authority over the 2 yet to ratify states should they decide not to ratify.
"1. The U.S. Constitution does not have a diffintion of what a State is.
2. The U.S. Constitution does not define the Union or name the States therein. "
I'm not sure how that is relevant. It was widely understood what and who the states were. There was no debate about the status of the 13 rebellious colonies. Here's Article VII : "The Ratification of the Conventions of nine States, shall be sufficient for the Establishment of this Constitution between the States so ratifying the Same." the language clearly says that there is an "establishment" of a "Constitution" or, if you will, -a contract, a compact, an agreement- "Between" the States.
Here's the Declaration making it clear that the states were initially, separate, independent and sovereign: "We, therefore, the Representatives of the united States of America, in General Congress, Assembled, appealing to the Supreme Judge of the world for the rectitude of our intentions, do, in the Name, and by Authority of the good People of these Colonies, solemnly publish and declare, That these United Colonies are, and of Right ought to be Free and Independent States; that they are Absolved from all Allegiance to the British Crown, and that all political connection between them and the State of Great Britain, is and ought to be totally dissolved; and that as Free and Independent States, they have full Power to levy War, conclude Peace, contract Alliances, establish Commerce, and to do all other Acts and Things which Independent States may of right do. And for the support of this Declaration, with a firm reliance on the protection of divine Providence, we mutually pledge to each other our Lives, our Fortunes and our sacred Honor."
"The Union of States was already declared, it was a state of mind, it did not require a Constitution to exist. "
Now you may be correct here, though that is really not the central point of the discussion. I'm sure many if not the majority of citizens of the states considered themselves still part of the Union while debating ratification. But my point is that they were free not to be and as a matter of fact and law, were not bound to any union. once the AoC union had been dissolved and replaced. rather, they were acting as free and independent citizens of their own state governments who had their own constitutions and acted independently in their choice to be members of the new union.
Good discussion David.