These are very difficult questions. I only can try to answer them as i wasn´t born at this time. But at least i can tell you what my grandma told me, who had to go through this time.
After the first wold war, germany suffered from the consequences of this war. (I´m saying this without any judging if it was right they suffered or not) Just take it as a fact. Germany had lost the first world war and life was difficult for them.
They were committed to assign large parts of their country, which meant a big loss of economic power to them. And it was not only a loss of income, it brought them into trouble to produce enough food.
According to the treaty of versailles, germans also had to pay pretty high reparations to the victors of the first world war. And they were forced to observe many restrictions like they weren´t allowed to have or build tanks or dreadnoughts and so on.
They had over 5,6 millions of unemployed people in germany in 1933. This was a rate of 30%, which is really high.
You perhaps can imagine, people weren´t happy with all these circumstances and life wasn´t easy for them.
And now there was Hitler, who had promised them a better life. He promised to build up more than enough jobs for everyone (for sure he didn´t told them he would mainly build up these jobs through a war). It was the early years of the 30´s and nobody (except Hitler and his crew) even thought of a war. So people believed in his words. And he did what he promised them, so there was no occasion for them to mistrust him.
From 1930 to 1939 the german folks were flooded by all these disgusting propaganda against jewish people. Note i´m not trying to find excuses for them, i´m only trying to explain why they believed it and why they didn´t had done something to stop it.
The jewish people at this time were pretty unliked by many countries, not only by the germans. That´s why Hitlers propaganda doesn´t sound that strange to them. And he never told the public that he was going to kill all jews, he told them he would like to emigrate them. There´s a big difference between killing and emigration. And yes german folks didn´t say no to emigrate the jews.
My grandma was 29 years old as the second war began. She lived in Essen (a big industrial city in germany, which was bombed out later) and worked as a saleslady in a bakery. The life she lived was the normal life of a woman in germany. She was not too much interested in politics. You may call her naiv or ignorant, but out of her point of view it was just usual.
At this time she was affianced with my grandpa, who worked as a office administrator. He also wasn´t too much interested in politics. They had planed to get married soon, build a house and become children.
Before they had the chance to put their plans into action, the second world war begun. My grandpa was forced to become a soldier and had to fight for germany. He later told me it was the worst time of his life and he suffered many years of it. He wasn´t a nazi, he was just a little soldier who fought for his country. Neither my grandma was a nazi. Yes both were members of the nsdap, but everyone was a member. There was no free choice. Nobody had asked you if you would like to be a member or not. You have had to be a member of nsdap, otherwise you would be brought to a concentration camp.
My grandma told me, she never knew about concentration camps during the war. First time she heard such a thing had exist was after the war. And yes she was shocked, of course! But she didn´t had much time to think about it short after the end of the war. Germany was destroyed and my grandma had hard times to survive with her two little kids. My grandpa wasn´t at home after the war. He was caught up by the russians and they brought him to a russian prisoner of war camp. The russians hold him in prison for 6 long years. You can say he was in this war from 1939 until 1951. The russians treated him bad, very bad. He was a broken man when he finally came home. He was ill, malnourished, had the badest nightmares you could imagine and became a drinker. He just can´t take what had happend without drinking. 40 years later he still had these nightmares and refused to speak about the war.
Please excuse my bad english. I know my grammar is awful, but i tried my best.