I guess I would say the high level functions of public key cryptography aren't that hard to grasp. Things like "hey either one of these keys can encrypt something the other one can decrypt and vise versa" is pretty straightforward. I don't think we have to teach the math involved if that's what you're implying.
Protecting the secrets words for a crypto wallet is pretty much the same thing as protecting the strong password for a password manager. If you lose that, then you're out of luck, and those are very popular.
You could also delegate trust in several places in the chain to trusted third parties if you feel the need, that could re-enable access, or shift assets into a new wallet.
I could get on board with the rest of your list, but this struck me as odd to include. Can you elaborate how it fits into that list?