Hi all - I have a paper wallet with a bunch of bitcoin, and I just want to send a little to my online blockchain wallet.
If I do this, and correct me if I am wrong, blockchain just sends the "change" back to my original paper wallet. Everyone says you shouldn't do this, but I don't really understand the risk. Everyone can see the public key of my paper wallet the second I load it, so why is there a risk in sending the change back to the same paper wallet and having my public key made public twice?
You cannot send bitcoins using a paper wallet because it simply doesn't have the ability. In order to spend the bitcoins in a paper wallet, you must import the private key into a wallet that can send bitcoins.
Once you import the private key, you should destroy the paper wallet or at least store it very securely because anyone that sees it can still spend your bitcoins. Also, you shouldn't reuse the paper wallet because the key is now in another wallet and that might cause confusion.
Blockchain.info has a feature where you can "sweep" the private key. All that does is sends the bitcoins from the paper wallet's address to a new address in the blockchain.info wallet. In this case the paper wallet is no longer useful because it no longer contains any bitcoins, but there is no reason why you can't reuse it.