I've used both BlockChain.info and Bitcoin-QT. Is it possible to use the same addresses on both? I don't have a incredibly large amount of bitcoins, so I'm not worried about it getting hacked into, however I am worried about it getting corrupt as it will be used in two different wallets. Is it possible for them to get corrupt by doing this? If not, how would I import the key to Bitcoin QT from BlockChain?
You aren't going to run into issues doing this, as wallets don't store transactions (technically), they look them up on the Bitcoin network blockchain. If you make a transaction on one wallet it will automatically update as long as both have downloaded the latest chain. For blockchain.info wallets this will be true and for Bitcoin-QT it takes a few hours to download the full chain.
If you're afraid of making a corrupt wallet accidentally, you can:
- Print out the private key for your addresses. Keep it in a safe place. An addresses private key does not change.
- Create an encrypted backup. Both wallets let you do this, your wallet private keys will only be able to be read with a decryption key; the password you set for the wallet. Anyone who will have your encrypted backup won't be able to do much if they don't know your password for it and password strength.
- Create a brain wallet and import it into both wallets. All your keys from the memory wallet will simply be memorized in your mind, where you can only forget it.
Check out these precautions as well.