Please make an effort as put forth as the ROEs suggest to read and search forums for information already provided. Much effort has been made to make information available and laziness insults that effort. CROs, STOs, & 13L ALOs Application Information
provides a lot of info pertinent to all your questions.
The nursing commission is a medical profession commission and not a non-rated line officer commission.
Cosequently seeking the nursing commission and getting it puts the individual in situation of not only being released from the nursing specialty for entry classification to become a CRO, but the professional (nursing) commission needs to be resigned and converted to a non-rated line officer commission.
If you become a CRO you will no longer be a Nurse. This means no nursing duties, no nursing continuing education and nursing experience necessary to sustain nursing credentials.
The risk of an individual with a health/nursing/medical profession commission is switching to line officer commission means if not selected during the two-phase application process or if fail to complete training is you will be stuck in some job like Intel, personnel, Security Forces or CE. Essentially the nursing degree becomes useless as no longer being a nurse mean not keeping license/credential current and up to date as a nurse.