1.you should pass the entrance exam, the physical exam and the 6 months training. you must be single, not pregnant (for women) or didn't bear a child, with license and I know there's an age limit here.
3. as what I know in the advantages as a military nurse (please correct me if I'm wrong), according to my interview when I was in first year college: you'll be a nurse and also have a rank, basic allowance for uniform, etc., government benefits like SSS, GSIS, etc., great work experience because you'll be assigned to different places in any kind of situations, chance for free continued nursing education here in the Philippines or abroad. They said that you'll have the advantage if you go abroad because of your experience and leadership skills.
There are so many advantages... I can't remember all of them. I suggest that if you're conducting a research, interview a military nurse yourself. Go to AFP, Fort Bonifacio or Villamor Air Base.
Also, there's this book ( I can't remember the name) that discuss about nursing in different setting. It also discuss about Philippine Military Nursing.