My Book Duo RAID 1 and encryption

I bought a My Book Duo 12TB. As I understand it, it’s hardware encrypted, and this will cause the disks not to be readable if transplanted into another enclosure, which seems odd since the whole point of having RAID 1 acknowledges that hardware components fail, and the enclosure is not somehow immune to that. I have several questions about that.

  1. This means I don’t have to use HFS encryption I suppose. The hard disks are always encrypted?
  2. What if someone steals my entire My Book Duo? How do I prevent access to it? My other external drives are using encrypted HFS; a thief would need to know the key.
  3. What if the enclosure dies? Does that mean my HDD’s aren’t readable from another enclosure?
  4. Is there a way to obtain/set the keys so the encryption can be configured by me?

UPDATE: I found a utility called WD Security that appears to allow me to set a password. This solution does make sense to me. For now I’m satisfied. I still need to run some tests to see how this behaves from another computer, if indeed not accessible from there, etc. but will not have the opportunity to do so for several weeks since I’m traveling.