> Use smartcard/physical-backed keys?
Basically, yes.
I'd be happy to share details of how I generated/store/backup my keys but be forewarned that I went the "extremely paranoid" route.
Please do. I haven't been able to find a vendor for smart cards in the US nor do I know exactly what to buy.
I would link to some here, but I don't even know of any best practices for keeping personal keys safe. (Use smartcard/physical-backed keys?)