If Europe can muddle along until 1917-1918 without a major international crisis, I think war can be avoided - by that point Russia's armed forces and civilian industry may have modernized sufficiently to reach parity with Imperial Germany, and the Royal Navy will well and truly have pulled ahead of the Kaisermarine in the dreadnaught-building race. From that point on Germany has very little chance of winning a general conflict, and is going to be far less likely to issue blanket promises of support to Austria over "some silly conflict in the Balkans" or the like.
Hm, you miss one point
why do you think that the french and russians (with the brits tied by secret contracts) do not start a war in 1917?
on the other hand - why should germany drop ah, its only ally?
also, why should the central power countries do so?
because the french just wait to crush le boche? because the brits want to destroy its economic enemy?
never - the only mistake of the germans was the faulty schlieffen-plan, with russia first they win the war, cause political trouble in great britain (the moment the british navy explain that they have treaties to lead a war with germany will be funny - if public hear about it)
ww1 is nothing you can avoid - the germans will be improved if the war is delayed. that sound silly if you know that the french and russian are to strong in 1916, but in truth the russians were paper-tigers... attacking germany and facing the strength of the german army will crush the russian army even faster. With france attacking germany - defending in the west - will bled them white much more, cause a german defence strategy means trenches from day1.
the us of a see the agressor (russia and france), sneaky brits that told something different (joining the war) and the blocade can (here you need some plots) cause so much trouble with the us of a (esp. if belgium and the netherlands stay neutral) that even a war with the usa is possible.
but this needs 20/20... and the germans doing anything right... and the entente doing a lot wrong (but still - a defence in the west and the bloodbath caused by the french offensive actions sound interesting)