I know the nazis had ideological reasons to view slavs as inferior and I know about the belief that the german people needed the land for themselves. But given the hatred for the bolsheviks, the nationalism, and the entrenched antisemitism in the Ukraine, it looks like easy work to play the part of liberator, not steely-fisted conqueror, at least until the war was over.
Why did the nazis not make any serious effort to win hearts and minds in the conquered territories of the western USSR?
There's a joke that comes out of the period.
Q: What did Hitler achieve in 3 years that Stalin couldn't achieve in 30 years? A: He made Ukrainians love Soviet rule.
You're correct to state that the Nazis could have exploited a potentially very sympathetic population by acting as liberators, and indeed, in the earliest days of the occupation, that's precisely what they did. There was significant population between the occupation forces and Ukraine's native fascist organizations, particularly when it came to the murder of the republic's Jewish population. In addition, since a major foe of Ukrainian nationalist organizations were the region's Polish population, many of whom hoped that the former eastern provinces (Kresy) of Poland would be reincorporated in their country at a later point, the organizations were happy to be given a free hand in persecuting Poles -- up to and including genocidal massacres of Poles by Ukrainian paramilitaries.
There seem to be three main issues that emerged, more or less, in the following order, that soured the Ukrainian experience against German occupation, and they are all based in the aforementioned Nazi view of Slavs and of the economic value of Ukraine to the envisioned future New Order in Europe.
First was Nazi policy toward Soviet POWs. Under the so-called Commissar Order, issued before the invasion of the USSR, German forces were commanded to execute on sight political commissars in military units and members of the Communist Party. Necessarily this number included some Ukrainians. More importantly, as the Nazis instituted their policy of deliberately starving Soviet POWs over the first winter of the war -- some 1-2 million eventually died -- the toll on Ukrainians was quite large. That some of these POWs were held and thus starved on Ukrainian territory made matters worse, particularly when locals near POW camps attempted to feed the starving prisoners and were punished to do so.
The second issue is the impressment of Ukrainian farmers into service of the civilian administration, the Reichskommissariat Ukraine, led by Erich Koch, which requisitioned grain to supply their own troops and population at the expense of the population. While the population was not left to starve to death like they had been under Stalin in 1931-32, there were sufficient privation to inspire resistance to Nazi rule. That Germany envisioned and, to a limited extent, settled its own farmers in the region, who were not subjected to such requisition, hardened the resistance.
Finally, toward the end of the occupation period, the Nazis began taking slave laborers from among the Ukrainian population for work in Germany, amounting to kidnapping in the view of the Ukrainians. By the time the Soviets began retaking Ukraine, a significant number of former collaborators switched sides and began fighting the Nazis. All of these policies contributed to that change.
A great book on the whole period of Ukraine (or most of it) under Nazi occupation is Karel Berkhoff's Harvest of Despair.