Questions I still have:
Would Germany stick with the Schlieffen Plan in a war against the Entente? If so, does it go better or worse than IOTL?
Are tanks still developed in 1916 or do they come about later?
Do the Germans still use submarine warfare against French and Russian shipping? If so, how does this affect Britain and America?
Does America still become a leading world power or are they still sidelined by the Europeans?
Russia and Britain were both looking to take over Persia before WW1- how is Persia affected by no WW1?
Given that World War One ITTL is (probably) between Germany, Austria-Hungary, the Ottomans, and Japan vs. Russia, France, and Italy, who would ultimately win this conflict?
1) By 1916 the Russian rail net will be good enough to make this risky (the Russians will be able to get their armies on the border moving sooner), unlikely the Germans could defeat France before the Russians can attack in strength by 1916, the Germans realize this (which is why war in 1914 was acceptable for them, the timing seemed good)
2) The firepower of the European armies by 1916 is going to become wicked, improvements in numbers and quality of machine guns and artillery will make it so, improving the power of the defense. I think its the Germans who are going to want to figure this out. A long costly war is their biggest concern.
3) As long as Tirpitz is around, the commerce war is secondary, the submarines will still be thought of as fleet scouts, a way to pick off crippled ships in combat, base defense. But with larger numbers of big rangy diesels subs, the Germans might figure out the commerce war part really quickly once war starts.
4) As someone mentioned above, the USA won't be expected to supply the world with stuff, progress and growth will happen naturally, the USA fleet is already a match for Britain for worlds largest, worst effects of great depression will be avoided, the fleet will be kept large because of worries about Japan (the Philippines), concern about German aggressiveness, the growth potential is very high, the USA will punch below their weight in world power plays, but there may be less power plays going on in general. A sleeping giant still sleeping.
5) As Persian gulf oil becomes more important, it seems like the great powers are going to be involved in the region more. But its in Britain's best interests to keep powers like Russia further away, so I think Persia can remain unoccupied, with "help" (Swedish Gendarmerie, or similar such thing to keep the Euro favorable peace).
6) People like "Stenz" are going to argue, with a lot of merit, that Britain isn't going anywhere, are going to be wary of Germany, and supportive of French/Russian interests over German because its in their own best interests, Britain+Commonwealth+Russia is going to be a hard combo to beat after 1914.
7) If 6 is true, war is unlikely to happen, the Germans will realize their weakness by 1916 and behave less aggressively, but no one is going to aggression attack such a war like country as Germany, who takes their military arts so seriously. but war will likely happen if Russia, Austria, the Ottomans revolt or break apart, changing the status quo