Hitler and Hell

I was thinking about one of the arguments for the existence of god and the afterlife: how do you process Hitler in your mind without the concept of eternal punishment and accountability? My mom has often brought up this argument and it has always bothered me on several levels, though I've never been able to fully articulate why in the heat of the moment because I fully share the sentiment that bad people should be punished.

The 'Hitler deserves hell' argument for the existence of god and the afterlife is basically an appeal to consequences of a belief, which is a logical fallacy. Nonetheless, in case my opponent remains unconvinced, I have written down various counter-arguments that will speak to hir train of thought. Punishing Hitler after his death is useless because:

a) It would not detract one iota from the suffering of the people he tortured and it would not undo what already occurred.

b) How much should Hitler be tortured in hell and for how long? Should it be the equivalent of the experiences of one of his victims or should it be repeated until all the victims are accounted for? I don't think that an eternity of punishment for finite actions is fair.

c) Even if the punishment teaches Hitler a lesson, it is too late for him to be learning the lesson because he is already dead and his actions no longer have consequences.

d) Punishing him may satisfy the souls of the people he killed, but that satisfaction is merely the base sentiment of revenge which should not exist in a holy place like heaven, in the presence of god.

e) Hitler was not solely responsible for all the tortures and deaths. He was able to do so much damage with the help of a lot of people. So you can't give him an undue amount of credit and ascribe him an undue level of monstrosity.

f) Hitler was mentally unstable, so can you fairly and squarely place all the blame on him? What about blaming his creator?

g) Hitler most likely suffered most of his life with mental anguish, and he definitely did not get off "scott-free" because he did commit suicide.

h) The notion that the expectation of punishment will prevent people from committing crimes is false because we have been jailing and shunning god-fearing rapists, murderers, and pedophiles for a long time, and they still commit crimes (often even after being released from prison).