Can bitcoin-qt use imported address as a change address? If I import a private key into a bitcoin-qt wallet, is it possible that some day some transaction I send from the wallet will use its pair address (the bitcoin address created from this private key ) as a change address target in the outputs ?
On Bitcoin-QT can use whatever change address you want. Go to Settings->Options->Wallet and check "Enable Coin Control Features". Now when you go to send you can check "custom change address" and enter whatever you want, even if you don't have the privkeys.