First, I believe Stalin was preempted by a few weeks. If Hitler had waited a month more, it would have been a Russian blitzkrieg all the way to France. The maps of Germany were already delivered to the troops, not quite distributed tohough.
Second, Germans went after Moscow with full force in 1941, and then after Stalin City, with full force, in 1942. In both cases, they were fended off, just barely. Going after Stalingrad made more sence than simple propaganda: it was on the way to Caspian Sea, Russia's only oil source back then (Siberia oil was not developed yet).
As to heavy industry - total agreement. By mid-42, it was already at Urals, quite out of reach of Germans.
(BTW, I checked the range of American bombers at the end of the war... America _could_ thrash all those plants behind Ural Mountains, at least theoretically, flying from England. That would be something to see.)