If Hitler didn’t attack Stalin, Stalin would have inevitably attacked Hitler. Granted Stalin was counting on Britain, France and Germany duking in out in the West in a war of attrition....with the Soviets swooping in and taking out the weakened armies.
You sound like you’ve studied background material on this a lot more than I have, but I can’t help thinking and thus opining that if Germany had essentially left Russia alone, played nice, and just consolidated into 1943, tossing Russia a few small countries as bones, Russia would not have gotten onto war footing, at least to the extent that they did once under attack in Barbarossa. Imagine Germany 1943 with no Russia invasion. Two years of consolidation and industrial buildup. Invincible. Stalin would attack such a juggernaut? Now Russia has the 1000 mile supply line?
I agree they hated each other. But I have never regarded Stalin as being all that eager to militarily attack Germany.