@annroberts: Good work! And now you’ve gotten your first 
on your first thread. If you would ever like a tutorial on the other features of the forum, you can always ask @cthulhubot for an interactive tour. There is an advanced version, too. Speaking of crypto… 
It’s not quite synchronistic, but certainly felicitous that your post was prompted by an email from Democracy.Earth. As it happens, we did a Cosmos Café talk on the Democracy.Earth white paper a few weeks ago, which would be a good place to start your inquiry:
https://www.infiniteconversations.com/t/cosmos-cafe-democracy-earth-white-paper-2-13/1726
At the same time, we can continue our collective inquiry with new questions. Of the ones you asked, I think the first, “What is Blockchain?” can be answered by a video on the other thread.
The next two are most interesting to me personally:
And I’m curious what others would think. How does “permission-less” relate to “consensus” or “consent” (as, e.g., the Quakers practice)? Is permission something we generally feel, or is it yet to be (mythically, or politically) granted? What are the technical implications (and constraints) of accountability, or how might we use cryptotech to “account” for our work together? Where don’t we want to use such technology?
@DurwinFoster, @care_save, and @adubalicious may also be interested in these considerations.
Your last question, about the connection to Metamodernism, is really interesting, too. I believe Metamodernism brings together “autonomy” and “communion,” seeing these as interleaving, dynamic facets of our being. And so the concept of “permissionless accountability” combines autonomy (in the permissionless part) with communion (or social responsibility, in the accountability part) in conceiving of a platform architecture with collective practices that would facilitate this integration. That’s how I see it generally, but the details matter.