It complicated...Nazisms did not persecute Christians in general and considered Christianity a part of the German culture. Atheists were persecuted, and so where members of sects like Jehovah's Witnesses. They wanted a church which was subservient to the state, and members of the clergy which opposed this or criticized the party were persecuted just like other political enemies. But the mainstream churches (Germany have both Protestant and Catholic) cooperated with the Nazi government.

Some Nazi ideologues were negative towards Christianity, but in general the system were positive towards "German Christianity".

Yes, especially with the condemnation of Nazism with the Mit brennender Sorge encyclical, which was distributed in 1937.

Not at the level of the Jew, but Christian organisations were suppressed and many priests were deported in camps.

See https://en.wikipedia.org/wiki/Nazi_persecution_of_the_Cathol...