I think it’s not just in graphic cards but also in appliances in your home. There are reasons why there is specific specifications within device and there is always a power rating that it requires and you should follow and not overload it. I think you just follow the appropriate amount of graphic cards in a single PSU and you are good too.

I think people overestimate 2FA security.

Funds in exchanges are always at risky, using 2FA is good but it is not 100%.

For wallets such as coinomi, electrum, etc, 2FA is basically useless because the private key is all that you need to access your funds.

Nothing is better than keeping the private keys of your wallet in a piece of paper, in an offline environment.