I see you e done your homework. Are you military by chance? Yes, he should've smashed the allies at Dunkirk, but hesitated because he thought Goering could bring them down with his Luftwaffe. Attacking the soviets was a huge problem, but he could've won it had he not gone to yugoslavia first. And declaring war on the US when Japan wouldn't declare war on the Russians was a mistake too.
It was, sure, the Eastern borders were secure but he did anyways and had chances to finish the Soviets off but failed to make the correct strategic and tactical decisions.
In that regard:
- His orders to fight to the death in Stalingrad and losing Paulus and the 6th army was a huge mistake.
-Listening to Goering (About anything) and agreeing to do the disastrous airlift to an encircled 6th army instead of sending an actual relief column was a big mistake.
-Operation Citadel/Zitadel was in-reality a draw but he wasted more men, material, fuel and those shiny new Panthers and Tigers on it for no gain.
-Having Italians and Romanians guard the flank for the 6th Army during Stalingrad was a really bad move, no armor, poor training and they were smashed by the Soviets which doomed Gen/Field Marshall Paulus.
-Choosing Operation Barbarossa to begin before securing the Suez and the M.E. oil fields was, again, the wrong move.
-Choosing to begin the bombings of cities as terror attacks during the air war over Britain instead of continuing to pound the RAF airfields, factories and radar stations. Hitler had the RAF on the ropes during this time and ready to break. The British bomb Berlin, Hitler gets emotional and the rest is history. This was a bad decision in a long line of bad decisions fueled by his mental weakness and emotions.