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, check your public addresses.
Then enter the command dumpprivkey "your wallet public address here" without quotes into the debug console.
For the commend to work, your wallet must be unencrypted.
If your wallet is encrypted, you will need to decrypt it in the Debug console first. On order to do this use the command walletpassphrase "yourpassphrasehere" without quotes.
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.
After copying your private keys, lock your wallet again with the command walletlock. You can also clear your clipboard history and make sure you save your private keys information in a safe place. If you lose track of your passphrase or password and your private keys will be the only way to access 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. Now you are more secure, in full control of your funds and do not depend solely on your passphrase or wallet.dat file.