> Also, maybe Heisenberg didn't want to succeed? Has that ever been resolved to some degree?

From the Farm Hall transcripts, it seems that Heisenberg was "happy" to have been working on a reactor and not a bomb, but from context, this seems less like an objection to the principle of working on a weapon and more like gratitude that the Allies couldn't hang him for working on an atomic bomb. Recall that the conversations took place after Germany had been utterly defeated and the scientists were prisoners at the mercy of the British--prisoners in a gilded cage, but prisoners nonetheless.