Rank depends upon age. If you're above the age of 15 you will begin as a Private. If you're below the age of fifteen, and are accepted as such you'll begin as a Trainee, under a probationary period. Right now the primary bases is focused around Destiny, but there seems to be quite a bit of people who are using BF4 as a filler. Thus far, game nights seem relatively lax, but dependent upon your Captain. Via the website, under application, and I don't think I understand the last one.