All of which they perfomed unilaterally, including coining money, enterered into treaties, alliances, and confederations. Georgia was not a member of the Articles of Association, nowhere in the DoI does it form any "union" to which independent states are legally bound. What constitution was formed? What document delegated powers?
The coining of money is not an attribute of an independent country. Under the Constitution, individual states are permitted to coin money. That argument is utterly specious.
The "Articles of Association," while an important benchmark in the development of American nationalism, does not purport to be the work of free an independent states, but rather colonies. In fact, the text begins as such:
"We, his majesty's most loyal subjects, the delegates of the several colonies of New-Hampshire, Massachusetts-Bay, Rhode-Island, Connecticut, New-York, New-Jersey, Pennsylvania, the three lower counties of Newcastle, Kent and Sussex on Delaware, Maryland, Virginia, North-Carolina, and South-Carolina, deputed to represent them in a continental Congress, held in the city of Philadelphia, on the 5th day of September, 1774, avowing our allegiance to his majesty ..."
The key development from this association was the Continental Congress (which Georgia belatedly joined). the Continental Congress would become a revolutionary body and act as the national legislature. In fact, within a few days of declaring independence, Dickinson would submit the draft Articles of Confederation, the nation's first constitution, to the Congress. The Articles captured the procedures already in place within the Congress. In it, Congress had the power to regulate foreign affairs, war, the postal service, the military officers, Indians, and monetary issues of state.
The authority granted was a "national" one, which reflected the "perpetual union."
The AoC&PU were unanimously adopted and in force by 1781, two years prior to the treaty which officially ended the Revolutionary War.
If you doubt that "union" was the goal of the Declaration and the same Continental Congress that wrote it, consider these words from the July 12, 1776 Dickinson draft of the Articles:
"The said Colonies unite themselves so as never to be divided by any Act whatever ..."