A great popularizer of psychedelics - a real-life Walter White. To his credit, he doesn't shy away from the fact that some people never return from their trip. That happened to my cousin.
Sasha Shulgin was a true hacker with a great heart in real life.
But to your second point, yes, HPPD[1] is a serious condition.
[1] http://en.wikipedia.org/wiki/Hallucinogen_persisting_percept...