So far so good, but how can I make sure the private keys are really working once I need them?
It might sound a little paranoid, but think of this scenario: I have 100 bitcoins in one of my offline addresses and wanna touch them a couple of months later. I try to import the private key and bitcoin-qt tells me "invalid private key" or something similar. It turns out that there was a bug in Armory and my coins are gone forever.
Of course, I could just import the key once into my online client to make sure it is working and then immediately sweep it. But that could expose it to a screenlogger.
Any solution for this?
Run Bitcoin-Qt in an offline computer and try importing the private key there? If it generates the same bitcoin address as Armory did, then you can be pretty confident that they private/public keypair and address are all correct?