ohhhhhh so many points to debate! I'm gonna drool!
Out of the line of your post, wich I totally agree with (Hitler was a disaster as a military leader) I'd have to argue about:
1- decision to stay and fight at Stalingrad. That I already spoke about in other thread. Probably the whole lot of Army group A and B, and Army group Don were saved by this decision.
2- Dunkirk: there was a natural reluctance to use panzers to finish off the pocket. The surroundins of Dunkirk are very tank unfriendly and the panzers were in not very good conditions after the attrition of the fast run towards the cost. At the time they were seen as indispensable for Case Red, and almost everyone betted that the fall of france would mean the end of the war, so he didn't risk them. It was a bad call, but I think that most military leaders of the time would've agreed with him. He had the backing of the OKW, for instance, in his decisions to stop the panzers.
3- Normandy was a dead end for the Germans. had the panzers stayed at the beaches they'd been wiped out by direct naval gunfire. Hitler had already given an order to stand in the beaches at Salerno and the HG division was almost wiped out of the map as soon as they approached the beaches during the counter attack. It was not a valid option, and he knew it.
The alternative was to use a movile strategic reserve, or a "fire brigade" as you call it. The problem is that there was no strategic movement chances for the german with all the french railway network destroyed, so they didn't help aswell.
but here it was a close end, one decision was bad and the other was as bad as the first. Hitler went with one and that was the bad choice...but the other wasn't any better, tbh.
4-the assault rifle decision...well, in his reasons Hitler had a point. The german industrial effort was already a mess, and to add another ammunition to produce on top, didn't look as a good prospect. The weapon itself didn't appeal a lot to him (or others,tbh)...previous tries to achieve a portable automatic rifle as a standard piece of soldier equipment werent successful (the last one was the FallschirmGewehr 42, and that wasn't exactly a success). All in all he was wrong in his opposition ,but at least had some seemingly (at the time) solid reasons to back up his stance.
5- the only reason there were so many 262 fighters so early in the air was because hitler pushed the program, no matter he wanted them as bombers. In fact the 262 fighter was in service BEFORE the 262 bomber, and it was in service the soonest it could've been no matter what. I once wrote a article about it backing up this opinion, but its in spanish and I should translate it. I'll eventually do it here
All the others, I agree with you