I'm confused

I a little confused on the matter of the Pre Order thing. I have my card thing, but I have some questions.
1. Can you use the Day Early play Code on an exsisting account or do you have to make a new one for that?
2. Do you have to make a new account for the Weekend Beta Test or can you use an exsisting account.
Just note I do have the codes

Anyone

For the beta weekend if you have a free slot in your account you can use that and play in the beta. Otherwise send yourself an invite/use one of the invite a friend code

The day early can be used on your existing account only by having GW Factions before the release. You'll need to install it and join it to your existing GW Prophecies account.

The day-early key, which is also the key which adds the preorder items, should be added to the account that you intend to use for Factions.

If you intend to merge accounts, i.e. add the Factions retail key to your Prophecies account, then you should use the preoreder key on your Prophecies account.

If you intend to set up a separate account for Factions, then you should set up that account with the preorder key.