Exporting your private keys is what you as a user need to do in order to have full control of your funds.
Remember that each time you create a new address you by default will also need the private key of that said address if you require a particular balance on that address or just for convenience. The QT wallet doesn't display that private key unless you the following procedure.
To start go to the "Help" tab in your QT Wallet and select "Debug window".
When the debug Console opens you can proceed on looking for the public address that you have on your directory on your possession
You will then input the command dumpprivkey "your wallet public address here" without quotes into the debug console.
This will apply if you don't have your wallet encrypted.
If your wallet is encrypted you will need to first decrypt the wallet in the Debug console. In the Debug console use the command walletpassphrase "yourpassphrasehere" without quotes.
After doing this will display the log as shown below.
Type the command as shown below.
After you perform this you can proceed again with Step 2 of this guide.
Lock your wallet back when you finish copying your private keys by doing the command walletlock. You can also clear your clipboard history and make sure you save your private keys information in a safe place. You never know if you lose track of your passphrase or password and your private keys will make you gain back the access to your funds.
After typing the command walletlock you will see a message of the QT wallet returning back as null. After this, your wallet will be effectively encrypted again.
You have finalized the process of exporting your private keys and the good thing about this is that you are more secure and in control of your funds and not depending solely in your passphrase or wallet.dat file.