To what end? How do you foresee this force of heavy bombers being employed? The Americans and British produced fleets of heavy bombers the Germans could never hope to match and yet they did not win the war for the Allies. Even with a significant heavy bomber force I can't see them significantly wrecking either Soviet or British industry with them, and American industry was forever out of range.
Depends. There is a pretty convincing argument made in this book that it did:
https://www.amazon.com/gp/product/0807858501/ref=dbs_a_def_rwt_bibl_vppi_i1
The thing is they only hit the right target towards the end of the war, so the economic collapse was ongoing as the country was being overrun.
I doubt the Germans were realize the key vulnerabilities in the British system and be able to sustain the pressure, but the Soviets were much more vulnerable once the German had penetrated so deeply into the country and pushed the Soviet economy to the brink. The were vulnerabilities due the concentrated electrical infrastructure that was regionally based without a national power grid that would allow for compensatory shifts to make up for damage. Plus as with the German economy the demand for power was on the edge of exceeding production ability, leaving little to no room for damage to or loss of even a single station. There may or may not have been room to repair damage eventually internally or at least source it from the US, but that would take a lot of time and expense if even possible, so damage to region electrical infrastructure would cause a lot of damage for limited investment of aircraft, with little if any need to launch follow up raids provided the first one hit the target.
Potentially the bigger problem for the Luftwaffe is the lack of strategic bombing focus until too late and of course Hitler frittering away the bomber force on stupid side projects (Steinbock). Some of that may have changed if there were strategic bombers ready in 1941, but given the dumb waste effort on bombing Moscow in 1941 instead of doing something productive like army support, the odds aren't necessarily great that the Luftwaffe would go after the necessary targets before say Hitler intervenes and diverts them.
The only real usage (of importance that is) would be to strike at Soviet industry. And that is also a bit 'iffy' as escort fighters would still have to provided.
Escorts weren't necessary except if attacking so very well defended targets, which would be incredibly dumb to do even with escort (Moscow proper). Outside of Moscow and Leningrad the PVO, the air defense organization that handled defending cities and other stuff outside the front lines, was highly limited especially in 1941-42. Moscow proper was insanely well defended, Luftwaffe pilots said it was worse than bombing London and probably one of the very most heavily defended cities in the world, but the areas in the wider Moscow oblast were not, which is where enough of the electrical infrastructure was to cause serious problems if attacked. Even in 1944 it was said to be poorly defended enough that if they attacked in somewhat 'dirty' weather they wouldn't need any escort and losses would be low. Even the He111 could operate generally unescorted even in 1944 in many areas, which was a death sentence on other fronts.