You need to be certain ranks to be able to be a Staff Member. This is because I think that some people will sign up apply for something then leave. The ranks you need to be are...
:@: Bodyguard - Spy
:@: Cdt. - Bot
:@: Ensign - Dominator
:@: Fleet Admiral - Global Dominator or Any Above.
However there is one Staff position where rank does not matter as long as you are active. This job position is the GFX team, you need to prove some form of skill in picmaking to have a chance of being a GFX Team member.