HueyLong, this is an interesting concept for a TL here. The POD is that The US in Congress Assembled is allowed to tax (impost). From what I've read it seems that this tax is on foreign trade, which shouldn't be too hard to get by the various States and it should be able to provide some money for the Congress government to actually work....but a couple of things seems a bit out of place:
1. If the POD is in 1781 and is basically just that Congress is allowed to raise its own revenue via tax, how is it that Virginia gave up the Kentucky area to US government control? In OTL Virginia ceded all claims to areas north of the Ohio River (which it called Illinois County) with a provision that a set of lands variously called the Virginia Military District or Virginia Military Lands were reserved for its veterans of the ARW - sort of like the Connecticut Reserve. The cession happened around 1784, while Virginia definitively kept control of the land south of the Ohio (over which it had much greater control). In 1784 Jefferson put his proposed Ordinance before Congress, but his proposal was modified by removing references to a ban on slavery and removing the proposed names and boundaries of Jefferson's states (in addition to making a few additions). In your TL, you have a 1785 Northwest Ordinance, but that Ordinance cannot possibly cover the Kentucky/Caintuckee/Pelisipia area because the Ordinance was specifically designed to cover the "Territory Northwest of the River Ohio", while Kentucky/Caintuckee/Pelisipia was south of the River Ohio. Pelisipia/Caintuckee would have fallen under the purview of the Southwest Ordinance of TTL....assuming Virginia had even ceded it which seems doubtful considering that the POD gives no clear reason for Virginia to do otherwise than it did in OTL. If anything, "Caintuckee" (according to wikipedia's article, the various forms and supposed etymological origins of "Kentucky" all ended in either "-eh", "-ee" or "-y", not just "-tuck") might be formed as in OTL but it might be formed earlier than 1792 if reasons can be found.
2. A 1785 Northwest Ordinance would still not cover the whole Northwest since Massachussetts still had a claim in 1785 (although in TTL it probably would have dropped the claim in time for the Ordinance) and Connecticut still had a claim in 1786. At the very least Connecticut would dispute the Northwest Territory's governor's authority in its claimed area and would probably not vote for the Ordinance.
3. By 1785 more member of Congress had begun to disapprove of the idea of having 10 States being formed from any ceded land in the area Northwest of the Ohio as Jefferson had proposed. They had begun moving towards the idea of having fewer States being formed with a higher threshold population for admission (Jefferson's original proposal only required 20,000 people for Statehood but also seemed to require that any future State have the same population as the least populous State in the Confederation already for voting representation -the 1787 Ordinance simplified it to having 60,000 people for Statehood and voting representation). Combined with Virginia's retention of territory south of the Ohio then at most only 9 States could be formed and most likely that number would have been whittled down to a range of 5 - 8 States, with some members of Congress arguing for even less.
4. Arthur St. Clair becomes Governor in 1785. Does this mean he doesn't become a delegate of the Congress for Pennsylvania and become President of the United States in Congress Assembled in 1787?
5. In OTL the only State to cede territory Southwest of the Ohio to form the Southwest Territory was North Carolina and the cession was essentially Tennessee. As stated before Virginia never ceded any land south of the Ohio River (since it had a lot more control over that land than over its claimed Illinois County - Virginia's land south of the Ohio was first organized as Kentucky County before being divided into 10 different counties) and Georgia didn't cede its western lands until 1802.
6. I am not sure how a state of Franklin would develop or if it would even be accepted, but if a Southwest Ordinance covering OTL Tennessee was passed in 1785 instead of 1790 (OTL's Southwest Ordinance was passed under the Constitution instead of the Articles), then it might be possible that a population threshold of 20,000 would be in it (although this threshold might be altered in both the Southwest Ordinance and Northwest Ordinance in new, amended Ordinances passed later on in the period between 1786 and 1787). If a population threshold of 20,000 was in the Southwest Ordinance, then Franklin might qualify (anybody know what OTL's State of Franklin's approximate population was?). The rest of the Southwest Territory might be split between Franklin and any new State (which might well be called Tennessee as Analytical Engine surmised) or it might just be turned into a new State, with Franklin remaining a small State.