Possible to alter user account status options on user_register_form?
Finished working through the implications of this and have confirmed it is not possible to alter the user_status fields through Drupal without causing other complications through other modules -- the 0/1 logic for users is too ingrained in core to overcome. 

I've addressed the requirement through a number of other Drupal hooks that work alongside the user module, will be releasing user_reopen module shortly to community.