Some of the answers to your questions are addressed in two books I have seen, see the book excerpts below. Early on in the war, by OTL March 1915, France and Russia were clearly determined to partition Germany. Their joint intent was made even more clear by February 1917. So it is very likely that their aims would be similar in your ATL after the announced POD.
In brief (again see the extended explanation in the book excerpts at the end of this text), the French were to have the Left Bank of the Rhine, including Mainz. Russia would extend its borders westward into Germany. Prussia was to be kept isolated from the other German states. The other German states would be turned into neutral states pending a settlement at the Peace Conference.
Also by March 1915, both the British and the French had agreed that Russia would get Constantinople and the Straits. The British were to be given the neutral zone that existed between Great Britain and Russia in Persia (there had previously been a northern Russian zone, a central neutral zone and a southern British zone in modern day Iran). The Russians were willing that the French get Syria, Cilicia and Palestine. The British would annex Egypt.
The postwar situation would seem to be quite volatile. Could Great Britain prevent a partition of a defeated Germany that millions of French and Russian soldiers are intent on ? Could Great Britain then counterbalance a powerful Franco-Russian alliance that had essentially wiped the German Empire and Austria-Hungary off the map ? Britain had always opposed the strongest single power in Europe to maintain the “Balance of Power” but could she oppose both France and Russia at the same time if they remained allied ? From the excerpts below though, it seems that France was leery of, and suspicious of, Russia’s aggrandizement, so that might imply a break-up that Great Britain could take advantage of.
My guess tallies with my vote above: a Cold War with Russian Empire versus Britain and France.
Information about Franco-Russian plans for a partition of the German Empire in Peter Jackson’s “Beyond The Balance of Power: France and the Politics of National Security in the Era of the First World War", pages 146 - 147
Information about a Franco-Russian partition of the German Empire, plans for Constantinople, the Middle East and the “Great Game” in Persia in A.J. P. Taylor’s “The Struggle For Mastery In Europe: 1848 – 1918”, pages 540 – 542