This is the wrong forum for you. Your looking for the Verizon Note 3 forums. From what I read, your bootloader is locked.
You might want to check on your forums and see if you got the developer's version of the Note 3 for VZN. That bootloader is unlocked. Knox is a security feature, once you void Knox, you can't go back. It won't brick your phone or anything, you just won't be able to use Knox anymore. I might be wrong on the using Knox part.
Sent from my Sanmsung Galyxa Noot 3.