I'm pretty sure that he has recently said
These together imply to me that he favors libertarianism but idk, I could be wrong, I don't think he has ever really come out and said anything about his concrete beliefs on policy proposals. He also seems to not dislike Ayn Rand and talks sometimes about the power of capitalism, iirc.
Scott identifies as left-libertarian, so you're both right. Quoting "A Something Sort of Like Left-Libertarian-Ist Manifesto":
"[Some people] support both free markets and a social safety net. You could call them 'welfare capitalists'. I ran a Google search and some of them seem to call themselves 'bleeding heart libertarians'. I would call them 'correct'." [...]
"The position there’s no good name for – 'bleeding heart libertarians' is too long and too full of social justice memes, 'left-libertarian' usually means anarchists who have...
Cover title: “Power and paranoia in Silicon Valley”; article title: “Come with us if you want to live: Among the apocalyptic libertarians of Silicon Valley” (mirrors: 1, 2, 3), by Sam Frank; Harper’s Magazine, January 2015, pg26-36 (~8500 words). The beginning/ending are focused on Ethereum and Vitalik Buterin, so I'll excerpt the LW/MIRI/CFAR-focused middle:
Pointer thanks to /u/Vulture.