recruitment efforts aside the germans lacked the necessary manpower and the top down military leadership to win the war, thank god. tactically they were with out a doubt without peer. regardless many miscalculations were made by the polish corporal hitler. 1 allied reaction to the invasion of poland 2 the vast spaces and resources of russia 3 the ineptitude of italy in war 4 malta and it's absolute importance to the africa corp 2a the switch from targeting radar and air fields to civilian sites re britain. etc...
1. Allied reaction? You mean the "Sitzkrieg"? If Hitler had resolved to smash the U.K. before turning east the U.S. could never have had a meaningful impact in Europe. Letting England be was Germany's mistake. Underestimating England's resolve over Poland, which was too little and waaaay too late, mattered little. I will say that England bought civilization some time by resisting but let's not pretend that her outrage over Poland's demise ( a demise which her/our future ally the Soviet Union gleefully shared in) was a major stumbling block to Hitler. He turned east too soon, that's all.
2. Victory was within Germany's grasp in 1941 but U.S. entry into the war made a long war, the result of which would mean Germany's defeat unless she could conquer the Soviets quickly, likely.
3. Germany shared your sentiments and this attitude did nothing but contribute to her defeat.
4. North Africa was a sideshow. So was Italy. The Western Front wasn't much more significant. I think Stalin said it best (paraphrased): "Britain provided the time, The US the money, Russia the blood."