Like any program or protocol, there are probably dozens of attack vectors that might lead to an exploit in either the clients, or the protocol. I'm not 100% sure what it'd look like, only that Bitcoin is ultimately something written by humans that runs on computers, and both of those things have proven time and time again to be stupid.

And of course there's nothing different between a compromised computer contained BTC and a cash mattress fire. Yes, in both situations you lose all your money. You're missing the point.

And yes, of course, fiat and bitcoin share the same fundamental weirdness of faith values, the comparison was to gold and silver, not fiat. So the point you're making is moot.