Everything you're describing could be done with a git repo (also a cryptographically signed tamperproof ledger), 10x faster and with 1000x less baggage of a deeply scummy industry behind it.
The core problem to solve with your idea is proving that a piece of data that represents someone electronically (eg a public key) truly actually represents them physically. Cryptocurrency backed blockchain solves none of this any more than any other technological solution does, because it does nothing to tackle the actually hard problem, of making that physical->electronic link.
Keybase did it by not truly doing it, and instead providing a plethora of different ways that all somewhat do it, and left it up to the user as to whether they trusted that. So you can link your domain, your twitter, your reddit, your crypto wallet, etc. That still didn't actually prove the physical->electronic link, but it added evidence.