Re: How can you recover a CD key?
You need to contact the EA Game Advisors at: http://help.ea.com/contact-us.
They are the only ones who can check your account (on the back-end) and confirm that you've got the game registered. That allows them to authorize it on your EA/Origin account so you can download and install it.
AFAIK they will NOT give you your original CD-Key. But once it's installed, you can then see the product code by using the configuration utility from the splash screen.