AIUI, Ray Peat tends to base his views on science. He learned a good deal by reading scientific papers, and some from his own studies and direct observations. I don't think he just decides that if something is mainstream it must be wrong. I doubt that many people who read the science believe that radiation is harmless. Experts have a range of views about serotonin - in some countries, SSREs are apparently prescribed (where I am, SSRIs are more common).Ray Peat didn't learn about the harmful effects of radiation/ PUFA/ estrogen/ serotonin/ neo- darwinism/ genetic determinism in college.
If you don't think having an understanding of a field is relevant to well-founded views, then there is probably limited scope for discussion.