Both the French and Germans massacred millions contemporaneously, which suggests that Westerners were willing to massacre millions, so long as they have a reason. It seems likely that the British would have done the same if India had sought independence through war, and thus Gandhi's push for nonviolent tactics averted a potentially tremendous loss of human life.

As for the partition, not only is a single million the highest estimate of the death toll, Gandhi was opposed to it, worked to reduce violence during it, and was assassinated in part because of his friendliness towards Muslims and desire to improve Pakistan-India relations. I do not understand why you deride his fasting, as it appears to have been the most effective tactic available to him, and did actually influence those around him rather than just accrue karma.

I agree with you that Gandhi's letter to the Jews was probably bad advice, but will also point out that Denmark had a positive experience with nonviolent resistance (whether or not that worked against the Nazis because Danes were Aryan is unknown). However, prizes must be given to humans, and thus people are judged on net rather than for lack of blemishes. I am sure you are aware of reasons for Gandhi to be given the prize, and in the spirit of ahimsa plead you to perform a calming activity then return to this discussion with a clear heart.