It would be great if we could get a "offline" method to encrypt and decrypt these wallets
There is one. You just follow pooya87's instructions to decrypt the private key on your offline, airgapped system. Once you've done that, import it in to Electrum on the same airgapped system. Grab the address it generates, take the address only (and not the private key) over to your online system, and import the address in to a brand new watch only Electrum wallet. Let that watch only wallet sync up all the transactions, then create a transaction sweeping all the coins to wherever you want them to go. Move that transaction to the airgapped wallet to be signed, then move it back to the watch only wallet to be broadcast.By doing this you import the encrypted key, decrypt it, and use it to sign a transaction, all without it ever touching the internet.
(All the forked coins are also compromised... because someone can extract them from those Private keys, if they can "Clipboard" it.) 
