You could very well be right. I'm willing to give it a shot and see.
All I can say is that I personally see huge value in a social network for real people. Personally I am sick of arguing with what are likely legions of duplicate accounts/bots/russian trolls online. I want some reassurance that I'm not wasting my time and am actually reaching real humans in my interactions online.
Success to me is 1000 MAU. There are companies out there that do passport verification for a reasonable fee with a fair amount of free verifications to start with (which will handle 1000 MAU just fine). If the number of users wishing to take part is significantly higher then I will explore either ads or charging a small fee during registration.
I'm still very far from needing to cross that bridge though. Same for some of the other questions you've raised. I'd have to do a lot more research to come to a solid stance of what to do when government data requests come in. But I would guess that there isn't much choice but to abide by the request. If you want true anonymity from the government then this place will not be for you (but then I'd say not many social networks are for you in that case)
I see a lot of value in a network where I can be confident I am talking to real people.
As a user I can't do anything related to the passport stuff and I know many people who likewise wouldn't be interested in doing that, because we live in the states. A more "normal" approach here would be to use one of the government ID verification systems for your state ID. Most of us are willing to expose that information, since it's what you show when you go to the store to prove your age/identity.
I would stay the hell away from any site that wants a copy of my passport.
As for a new turing test there is a magic word that bots are not allowed to use that guarantees you're talking to a human.