There might easier ways now but Bitcoin armory X of Y paper wallets are the "easiest" to use while providing the highest protection. For example spread 5 copies of a document around the world and you would only need 2 or 3 copies of that document to recreate your keys. Even if your house floods or burns down as long as you can get the correct number of copies you're OK.
You need to ensure that the keys don't sign the transaction on the same computer. It would not be safe as it would be exposed to an attacker all at once.Offline. Put the wallet .dat files on a usb stick and keep them safe.
The wallet must have never been on a computer that has connections to the internet before. Doing so may result in your private key being compromised in the event that there is a virus infection.No it doesn't. All you need is to make sure your computer is safe. If you use a computer that is only ever used for bitcoin transactions then there likely isn't going to be any issues.
All of this above reminds me of the time before I got myself a hardware wallet. Non-stop paranoia, reformatting, checking and running anti-viruses and malware protections. It was hard to relax myself after I started using Trezor.
