Thank you for your detailed response.
I think it is usefull to also consider circumstances to understand (not justify) history.
AfaIk e.g. with the British DoW in 1939 and the british blockade, Nazi-Germany and its economy, which massively depended on imported food, energy and other resources, were doomed to collapse within the next years. The Soviet Union compensated this in 1939-1941 by supplying Nazi Germany with needed grain, oil, cotton, metalls, etc. but demanded military and industrial equipment in exchange. So even before Barbarossa the germans somehow lived from the soviet lands. The deadly dependency on Soviet supplies (and the fear of loosing a German - Sowjet arms race) was probably the main reason for the Germans to attack Soviet Union in 1941, outweighing the ideologic differences between fascism and communism. So when the german armies (3-4 million men) were in the east (soviet territory), they often had to somehow supply themselves with food and energy from the occupied lands since the mainland could not provide sufficient ressources nor transports to supply them permanently, especially in times of difficult weather (mud, extreme cold).)
The german dependency of eastern european agrar resources was already a problem during WW1 when Germany spoiled relations with new founded eastern europe states like the baltic states or Ukraine because they needed the resources asap to not collapse.
(Mis-)treatment of population was definetely influenced by Nazi ideology (racism), but also by the dependency of the troops on the land and the increasng partisan activity, which was part of soviet military strategy and not solely caused by german/nazi atrocities.
So was not solely caused by german or nazi evilness but also by economic and logistic circumstances and the general will to survive and not loose the war at all costs.
The amount of resource transfers from conquered territories into the german mainland to reduce war weariness and social unrest is a different topic.
(e.g. see Götz Aly : Hitler's Beneficiaries: Plunder, Racial War, and the Nazi Welfare State)