Regarding your first paragraph, I don't think the psychedelic experience is predetermined by the substance. There are common traits we all experience on a substance of course, but everyone has a different nervous system. Maybe Lilly even had a touch of schizotypal personality disorder, I don't know. Based on what I've read from Robert Anton Wilson it seems like Lilly was always a strange person, and difficult to understand. I see a bit of narcissistic grandiosity in him. In all his interviews and writing he never really acknowledges his research failures, for example. I think these personality traits could have contributed to his far out experiences and strange belief system. I think he really liked being seen as out there.