Downloading maps for free will only be possible if you connect to a wireless network and set this as your default packet data supplier. Make sure you get it right though or you'll be paying for the downloads if it connects with your mobile internet provider. You'll need to download manually though as I'm sure there is no way of downloading all of them at once. Best of luck with this, I tried and couldn't do it
Deleteing all text messages is really easy.
Messaging, inbox, options - mark all, options - delete, confirm