Lets not be overdramatic. With Malta out of the picture German supplies double
I'm hardly being overdramatic: removing Malta may double the amount of supplies getting to North Africa in general, but it does not at all double the amount of supplies getting
to the frontlines North Africa. There were several points during the North African campaign when Axis merchant shipping was getting through more then enough supplies to support Rommel's forces (all the way up to the full capacity of the ports they were shipping through), yet he still kept consistently stalling out within the Egyptian-Libyan border, give or take a few hundred kilometers. The reason behind this was the
other issue which plagued the Germans and which they never solved: getting the supplies across 850 kilometers of god awful desert wasteland from the port to the frontline. The trip was so long and over such terrible infrastructure that the truck columns which ferried supplies to the frontlines had to themselves be supplied by other entire truck columns... yet still, Rommel's forces way out in front were not receiving adequate supplies. The Axis (for reasons that remain not entirely clear) never did the one thing that could have solved this, build an adequate railway of sufficient, and thus an advance into the Middle East via North Africa was never a realistic possibility for them.
Overwhelming force and superior logistics. Unlike the Axis, the Anglo-Americans did identify the aforementioned solutions and built a rail line behind their advance that could supply their forces. Thus, unlike the Axis, the Anglo-Americans actually did have the means to actually support their never-ending reserves in theater.
OTL the Germans advanced until October and that was with half their supply sunk and with few reinforcements.
October was actually one of those times when Axis merchant shipping was able to get through enough supplies to the ports to support Rommel. The problem was that those supplies largely sat in the port warehouses gathering dust since they couldn't be moved to the front.
Would it? I doubt that: The American people favored early action against Japan,
And they got it even with the American commitment to Europe First: Midway happened in June 1942 and Guadacanal started in August and went right on to February 1943. A basic look at the calendar shows that this means the Americans had enough resources to prosecute Torch
and the Guadacanal Campaign simultaneously.
OTL Americans wanted to concentrate on Japan.
And they got their wish, in so far as the US was able to concentrate on both theaters. The US military may have given an ear to American public opinion in the conduct of their strategy, but they never let it
dictate their strategy.
Remove Stalin when he retreated to his Dacha after the encirclement of Minsk. That would likely have resulted in a power struggle or at best running the war by committee without defined leadership roles.
That's one potential, although the war winding up being run by committee does have the potential to improve Soviet prospects depending on the details. Another potential is Stalin finds out what is coming and attempts a pre-emptive strike (we've had a few threads on this).