Guys
Not quite sure what the starting conditions are as the link at the start refers to a thread ranking US Presidents. However from the snippets referencing talk about the state of play in eastern Europe I'm presuming that means something very near OTL in terms of the starting conditions.
I suspect that rules out one useful step, maintaining the Austrian empire in modified form. I.e. its core territories of Austria, Bohemia, Croatia possibly adding Silesia and giving a more democratic constitutional system. That would give a bulwark in an unstable region and reduce the level of economic disruption by the multitude of borders. Especially if you also managed to keep the Hungarian kingdom part of it, even if areas such as Bosnia were transferred to a Greater Serbia/Yugoslavian kingdom.
However how about a more draconian political move with a softer economic one. The allies give up most reparations, with possibly a few exceptions such as for Belgium. In return the US agrees to Britain's proposal that both powers cancel the war debts of allies. This avoids much of the economic instability that followed and you can probably butterfly away the great depression. Also it removes one of the sore points with Russia.
At the same time a harsher political line is taken with the partition of the German empire. A-L will be returned to France, I can't see any way to alter that. However the various states in the former empire are separated from Prussia which is broken into 3 parts. In the NW the kingdom of Hanover is restored and probably enlarged, including the German parts of S-H. This means that the rump Prussian state is isolated from the North Sea. The Prussian eastern core area around Brandenburg and the old provinces of Prussia stays under the dynasty and are responsible for the reparations that are made. In the west the industrial Rhineland is made an independent republic. [Possibly also Saxony restored to its per 1815 borders].
As such French and other neighbours are given assurances against Germany getting too strong. However there is much less need for hiving off parts of Germany to non-German states to try and weaken it, causing less resentment. By adding political divisions to the existing social ones between the developed west and the generally socially more conservative east, along with the fact the rump Prussia is paying the compensation you should have a chance of maintaining the division.
Given such a division there would not be a great need for military restrictions as the various rump states would, while in several cases significant regional powers, not be strong enough to pose a threat to their main neighbours. The treaty would seek to prevent the re-creation of a Great Germany, at least without the consent of the other great powers. [Which means its only likely path would be by diplomacy].
Steve