Trust is the elephant in the room. Does Ledger, Trezor, or multi-signature technology deserve our trust? You seem to be trying to eliminate trust by adding security layers. Can you ever be safe in the cryptocurrency wild west?
Dont even mention Ethereum. I agree; smart contracts are time bombs. Not "if" but "when" they'll fail. How could anyone trust Genosis secure when its reputation is no better than Ledger or Trezor?
Why store in USDC, DAI, and USDT when you can convert to USD and bank it? You state your country bans cryptocurrency trading. Well, theres your sign that maybe, just maybe, the powers that be know something you dont.
By that logic why keep your money in the bank? Government could takeover all of it and consider it as theirs to cover expenses of a crash, which they have done in a few nations. They had one in Cyprus if I am not wrong where they took the money right out of your bank account if it was more than a certain amount, to pay for something, I do not remember what it was.
So all in all we have to realize that it is not going to be easy to fully trust anything, what if you get gold and put it in a bank vault? You may get it stolen, who knows? Or what if you get banknotes and put it in a safe at your house? Could be stolen there too. All in all, if you want to look for the impossible, you are going to find it everywhere you look.