Yes you did, but you'll be getting a new one once open beta is released, so if you lost it no big.
And yes, if your FFXI and FFXIV account are both on your SE account, you'll get the discount, and no it's not for preorder, if for as long as you hold both accounts
And yes, if your FFXI and FFXIV account are both on your SE account, you'll get the discount, and no it's not for preorder, if for as long as you hold both accounts