Buy lots of cheap bitcoin, and start mining.
What about if bitcoin didn't exist for some really odd reason?
Then I'd re-create it, and buy lots of cheap bitcoin and start mining.
By die I mean completely gone,
Like I said, I'd re-create it.
price $0,
I'd get lots of free bitcoin, then I'd sell it to other people.
code was hacked,
I'd buy lots of cheap bitcoins and either wait for someone else to fix the bug that allowed it to be hacked or I'd fix the bug myself.
private keys exposed,
I'm very careful with my private keys. They won't be exposed. But if somehow they were, then I'd generate new private keys and be more careful with them this time.
bitcoin dead
Bitcoin isn't alive, so it can't die. People can stop using it, but, as long as I continue to use it, it will continue to exist.
There is always a chance, don't be a blind fool
A chance of what? That's like saying: "What if all the rocks in the world died tomorrow, what would you do? There's always a chance, don't be a blind fool."