Like I said, Germany's campaign against France actually was not the smashing success it is widely, almost universally, portrayed. Ironically I think the French are the most improperly-maligned (as a war actor) country in the world. In a few weeks, the French destroyed 20% of the Luftwaffe and a correspondingly large portion of Germany's armored corps, and some 50-60,000 superb troops. If the British hadn't sucked so bad, Germany would have lost a lot more.
First, among historians there is no thought that the French army, armorment vice, where the best in the world in 1939-1940 and that the French army strategicly had stagnated since WWI. Second German Panzer in 1939-1940 was nothing more that lightly armed and lightly armored vericles (Google Panzer II and Panzer II if you don't believe me) and the triumf of Der Dritte Reich in the spring and summer of 1940 was purely based on very bold attacks and the pure chok effect of the Blitzkrieg (Guderian and his troops could very easily have been cut of, surrounded and destroyed by a wellcoordinated army)
Hitler planned on taking out the French more easily (1871 style) and then negotiating peace with them and Britain. Once that failed, Germany was again faced with a 2-front war and inevitable American intervention... in other words, WW1-- but with a much earlier and stronger American entry (thanks to the Japanese) and with an infinitely stronger USSR (versus a disastrously weak Russia). That's a bad recipe in anyone's cook book.
You make some rater strange mistakes here. Germany wasn't faced with a twofront war when they failed to break UK in 1940. After the French defeat the only front was in North Africa and the only resistance was UK. Hitler choose to attack USSR 22th June 1941 and thus his actions caused a twofront war. The American entrance in WWII wasn't inevitable. The Isolanists were quite powerfull in the US and it is doubtfull that Rosevelt could have mounted such a massive mobilisation if Pearl Harbour never happened.
And last but not least. Treblinka, Maidanek, Sorbibor - all these extremination camps were "in action" from 1941, a point in the war where everything looked like Germany was winning.
