What an interesting topic! Here's my two cents' worth...
... One thing I haven't seen much is an Entente victory in 1914 or 1915. So, two questions:
1) How could this come about? No PODs before 1914 - i.e. you can have a country stay neutral or join the other side, but you can't say 'the Entente would be in a better position if the war was delayed to 1920' or whatever
Perhaps a different outcome involving the Ottoman Empire could shorten the war in the Entente's favor. Two possible examples:
(1) The British do not requisition the two battleships they were building for the Turks which had been paid for by the Turkish public. Hence the resulting OTL outrage does not happen, the entire Goeben/Breslau affair does not occur which indirectly led to the Ottoman Empire joining the Central Powers.
With the Ottoman Empire thereby probably remaining neutral or possibly even joining the Entente, this scenario results in Russia being assured a constant supply of arms and materials from Britain and France. Bulgaria probably won’t join the Central Powers.
(2) Churchill’s Gallipoli gambit succeeds in early 1915, thereby keeping the arms and material lifeline open to Russia and depriving the Central Powers of the Ottoman Empire as an ally and providing a second backdoor (along with Russia’s) to attacking Austria-Hungary. (three backdoors if you include Italy who declared war on Austria-Hungary in May 1915 OTL)
Other possibilities perhaps leading to an early Entente victory…
(3) Especially if the arms and material lifeline is kept open for Russia, there could be a chance for a devastating exploitation of Russia’s successful attack on Austria-Hungary in Galicia, with the victories of the Battle of Lemberg and of Przemysl. Couple this with an unambiguous declaration by the Tsar to establish an enlarged Kingdom of Poland, under the Romanov scepter, which includes Polish lands occupied by Germany and Austria-Hungary.
(4) The Lusitania attack leads to the United States entering the war on the Entente side in May 1915.
... 2) What might the aftermath be like? One would assume it would be much less punishing than Versailles, and presumably a lot of countries that in OTL were overthrown in revolutions wouldn't be.
Ideas?
Since the Slavs in Austria-Hungary wouldn’t have had as much time as in OTL to organize, Italy would have absorbed much more territory than she did per the secret treaties probably most of what became coastal Yugoslavia.
Germany, with the United States’ support buoyed by Wilson‘s strong sense of morality, insists upon a plesbicite in Alsace-Lorraine. In a big surprise, considering Allied propaganda, the Germans win the plesbicite, angering the French but some of the almost purely French-speaking parts of Alsace-Lorraine, including Metz, are nevertheless ceded to France by Germany, in a bid to curry favor with President Wilson.
There is no Schleswig-Holstein plesbicite.
Like a Humpty-Dumpty, Austria-Hungary breaks up and cannot be put back together. The aged Habsburg Emperor becomes solely the King of Hungary as German Austria and what later became known as the Sudetenland join the German Empire.
Hungary loses territory to Rumania but retains Ruthenia and adjacent Magyar-populated areas. The Czechs and Slovaks unite under a Romanov ruler to be determined. Slovenia and Croatia, along with Bosnia-Hercegovina are ceded to Serbia. Montenegro retains her independence.
Austrian Poland (Galicia) is annexed to Russian Poland. However the Tsar has second thoughts about a completely revived, albeit dependent, Poland consisting of all Polish lands. During the peace talks, Germany and Russia diplomatically align, similar to Talleyrand’s maneuvering France to side with Britain and Austria at the Congress of Vienna in 1814-1815. Therefore Germany retains her Polish lands, all of which have been under German rule since at least 1795.
All German colonies are to be returned to Germany except for Kiauchau, and the Marshall, Mariana and Caroline islands which Japan refuses to give up but agrees to a be-to-determined financial compensation for Germany.
In another bid to win the United States’ favor for post-war maneuvering purposes, Germany scuttles her U-Boat fleet, promising to permanently refrain from submarine building and proposes to Great Britain naval limitation talks which the British seethingly resent.
Germany promises war reparations for Belgium and France.