Another reason for the failure of the Schlieffen plan (and the Russian deafeat at Tannenberg) was the fact that most nations were oblivious to the fact that the enemy could listen to their radio transmissions. When the enemy knows your weak spots, don't be surprised if he attacks them.
I have played Germany three or four times now and always moved troops away from the left flank, only leaving 4 divisions to guard the forts not 16, and reenforced the right flank. What really determines the speed of your advance in France after taking Paris is your manpower growth. But usually France fell before Italy decided to join the war via event, only to peace out via event, because France had fallen.
In one game though France decided to fight on and for whatever reason (maybe to much of my colonies had fallen to the British) the second French surrender event did not fire even after I had conquered all of (European) France. They spammed me with peace offers instead.
The AI is usally surprisingly good although France sometimes leaves Verdun empty to fight my reft flank - not too smart an idea.
Another oddity is when you manage to sink the British Home Fleet defending the Home Islands they keep the rest of their fleet wherever it is (preumably the Mediterianian). So after a few very hard fought sea battles, you can land your veteran troops on the Home Islands and capture them without encountering more than small and easy to defeat small flotillas, even though the Royal Navy has still more ships than Germany.
There are still some things puzzling me:
-Why doesn't Germany release Crimea as part of Mitteleuropa? It seems strange that every peace of land taken away from Russia is given away to satellites except this one.
-What are the sleep_party commands in event 28528 (The Central Powers Win the Great War) supposed to do? After the event triggers the old parties are still around.
You have created a truly great mod, keep it up!.