How do I send money from imported keys to my localbitcoin wallet?
First of all, there is no need for importing your private keys anywhere else if you want to keep them safe and inaccessible by third parties such as localbitcoins.info. You can simply create Output transaction from your desktop PC from MultiBit wallet to the public key that is presented in your account on localbitcoins.info.

For more information how to create transaction follow guide from Multibit - Send bitcoins