Very well written!

We need an open, extensible, and free smartphone platform with a fully free and adjustable operating system. We need a distributed, encrypted and private social network that may run on it
[...]
Some of these things (like the social network, and the operating system) already exist

Can you name them?

I heard about Synereo and Akasha distributed social networks, but they're still under development or alpha stage. I also tried Diaspora*, but it feel like desert, not giving any search results.