I'm not sure about the harm buddhism has done, it was at one point a warrior religion, the temples developed the martial arts and fighting styles and I understand that's for a reason and had its corrollaries or parallels in the European context when the monastaries had to fight off vikings and raiders. The monastaries were sources of soldiers for the crusades probably too but I'm not sure it was the same in contrast, at least not entirely, I dont think its because of the hegemony of the east in martial arts until the emergence of MMA either.
There are other more spiritual reasons for believing that about buddhism but I'll not automatically assume you're interested in that on the back of what you've said about the important of temporal thoughts, words and deeds, I understand that's important but my concerns for spiritual, strictly spiritual, aspects of any faith isnt shared by everyone and I know that.
I knew that the bicameral mind theory involved all hallucinations, although my understanding of it is that it is not simply attunement or discernment to external divine or cosmic messages and consciousness but that all hallucinations and consciousness were organic, therefore it lends itself to atheism and the possibility of any afterlife. I think its important to acknowledge that there's a possibility that both psychological and social or environmental change influenced peoples thinking and did result in delusions or illusions but that does not mean that all beliefs are erronious, I appreciate your clarification of your view.
One thing about the "religion is all in the mind" theorising, which has been borne out in some experimentation and can be triggered with electrodes, is that it cant explain stigmata or other miraculous phenomenon in the body besides the mind and not associated with mood or cognition. Curiously there is a region of the world, an island, practicing ancestor worship or at least fear of ancestor spirits, in which researchers have all experienced bleeding and cruciform wounding, its unexplained but typical in its occurence, irrespective of any kind of religious experience or practice.