So this is what I've figured:

• Download bitaddress.org and copy to offline computer. Generate private key, address offline from it. Make paper wallet
• Send btc to this address
• Setup Electrum wallet with a seed on offline and online computer.
• SWEEP the key into OFFLINE Electrum wallet. This will not import the key, but transfer the bitcoins from that address to the electrum wallet address.
• Sign an offline transaction made by Electrum (to send some btc to a exchange)
  
• Execute the signed transaction on Online computer Electrum

Am I doing anything incorrect?

In the SWEEP the key into OFFLINE Electrum wallet step, since the wallet is offline, Sweep won't happen, right? What should I do then?