It seams that if I and my wife wanted the same purchased Bible, we would have to register separately:

1- Do we have to pay separately for the same Bible?
2- If yes, then is there a discount for the second one?

I'll second that comment/request. My wife was using my iPhone, but she recently bought an iTouch. I loaded the bibles on her iTouch using my account, but she is stuck with my notes, bookmarks and highlights. We at least need a way to have a sub account.

Please contact our support department about these issues. Thanks.

I contacted support but still have not gotten a reply.

Your messages may be getting stuck in your spam folder. We've responded to all messages received about this.

I have the same question, can you please clarify how can this work?
Thanks!

We now support the same user name on up to 2 devices, as long as you own both devices. So if you own, say, an iPod Touch and an iPhone, you can enter your user name on both devices and share your purchases between the 2 devices.

Bookmarks, notes, highlights, etc. are all stored on a per-device basis, so if you backup and restore notes, these are kept separately for each device. If you upgrade your device (say you move from an iPhone 3G to a 3GS) and you back up your bookmarks and notes, they will NOT show up on your new device. You can, however, contact our support department and we'll be happy to copy your backup file from your old device to your new one.