jgack: while I agree with most of what you said, giving Imperial Germany all of Europe will make it the undisputed master of the world; the US will never have been pushed into becoming a major world power (to refer to Yamamoto, the sleeping dragon would never be awakened). Also consider that Europe was, at this time, the absolute leader of the world; both Britain and Germany could have defeated the US in an actual war (the British navy would have dominated the US', and the German army would have run all over the continent. Hell, the Americans actually turned down the Lewis machine gun).
Remove Great Britain, and give all of Europe's resources and infrastructure to the Germans, and within twenty years the German navy will dwarf anything the Americans can produce, and the German army will be then what the US army is now in comparison to other armies in the world.
There is one thing I am consistently dissapointed at in the forums, and that is the assumption of most people that the US cannot lose. World War I, World War II, and the Cold War are all assumed that "the US wins as soon as it gets involved," and any POD having another nation militarily defeat the US is seen as a farce (for example, it's been oft stated that the US cannot be invaded, and yet there are no problems with the US invading others, though it has to cross the same distance). Here are some ways for the US to get involved in and lose World War I:
POD: German general does not drive his automobile straight into a French patrol, and so the French High Command doesn't realize that von Kluck's First Army is going to hit the British at the Marne, rather than the French Sixth Army and Paris. Thus, the French Fourth Army is sent to defend Paris from a direct assault that is not to materialize; instead, the Germans strike hard at the British, who are still disheveled after the loss at Mons, and drive a wedge between the British and French forces. Panic sets in and the British retreat to the coast, as their breakout attempt is beaten back at a heavy cost. The Germans continue with their encirclement, attacking Paris from the rear, and General Gallieni, the military governor of the city, is killed by an artillery blast. The French retreat south, but the war is over; the Germans continue to chase them south, inflicting defeat after defeat on the now completely demoralized and broken French army, and France finally surrenders on Oct. 8th. The British army, at full retreat, fights the Germans all the way to Dunkirk, where the might of the Royal Navy holds the Germans at bay until the BEF is evacuated.
France formally surrenders to Germany, and cedes the remnant of Lorraine that it had retained since the Franco-Prussian War. Germany honors its vow to Belgium and returns all Belgian land, as well as paying an indemnity to Belgium (which Germany extracts from France in the peace treaty). In the east, the Russians are being smashed, left and right, by the German armies that are now reinforced by the armies from the West, and the defeat of Russia seems all but certain. Great Britain, however, refuses to surrender to the Germans; Lord Kitchener becomes an inspiration to the people when he states that the British will "fight them on the rolling French hillsides, fight them on the snowy Russian plains, fight them on the high seas and in the heart of Germany itself. We will never surrender." The Royal Navy continues to hold back the High Seas Fleet while maintaining a large enough force at home waters to annihilate any possibility of a German invasion; without the skyrocketed army costs of OTL WWI, the Royal Navy grows even larger, as dreadnoughts, battleships, cruisers, and destroyers are pumped out as fast as the shipyards can make them. Furthermore, the BEF, now filled to the brim with volunteers (and, with the British now understanding that a small, professional army means diddly squat, much larger) is sent via India to Russia to bolster the Russian troops. The BEF succeeds, here, and the German advance into Russia is halted when the Germans encounter what the British refer to as the Royal Line, a series of incredibly fortified trenches that are impervious to anything the Germans throw at them. These lines are manned by Russian troops, eager to get out of the field, and Russian losses plummet.
The Germans, realizing that, if they are unable to swiftly end the war in the east, France might rethink its surrender, are quick to seize French military equipment, including the quick-firing French 75s, which they put to good use in the east. Furthermore, seeing that the British are the props holding up the Russian army, the German command undertakes a policy of unrestricted submarine warfare to stop the flow of resources to the island nation, and starve Great Britain just as Great Britain had intended to starve Germany.
It's really late... I'll continue this in the morning.