> My only point is that having a substantial amount of faith in anyone, when the stakes are high, is folly.
Because he has credibility due to his track record. That's the basis of how networking works. The authors of software such as TLS, Whonix, Tor, Tails, Debian, all have a certain amount of credibility within their peers as well as the general public.
We stand on the shoulders of giants.
Yes, credibility can be abused; as a matter of fact, he did abuse his credibility. Snowden broke his credibility to the NSA (and US government), but for a greater good of both the people of the USA as well as the international community. The price he paid? He lost his well paid job, he lost seeing his family and friends, he lost the luxury life in the USA, his house and any and all of his assets, and a substantial part of the USA hates him (tho a more vast, significant part in the world, is thankful). Ie. his credibility with the rest of the world has substantially increased.
Now, you may think he may abuse his credibility, and it'd be a great plot for a movie, but that doesn't make it realistic. And why? Isn't the same true for any programmer on Zcash, Bitcoin, Etherium, and anything else? If you claim you cannot trust anyone, how can you live with yourself? Are you sure that's air you're breathing? Are you sure the color white is white? You'll end up with a full blown paranoid psychosis if you go with that line of reasoning (speaking from personal experience as well here). My point is that, at the very basic level, we need to trust and take some basics for granted (and, all of us do).
So what we need from you, is some kind of facts (not theory) as to why we cannot trust Snowden. The fact, as far as I can tell, contradict what you wrote: Snowden hasn't acted in the past based on financial gains. For example, he didn't sell NSA information to media or foreign agencies. Instead, his actions were solely based on moral grounds plus personal survival (hence he ended up in Russia).
I'd like to end my post that, yes, people who are psychopaths would very well end up doing something you described. I have no indication Snowden is a psychopath; tho I'm not sure about those he worked for at the CIA and NSA.