It depends what kind of admin/staff you want to be.
They work in different "teams", you see, even tho they are a group of people who put together the whole staff team. There is different administrators, such as Player Relations, that take care of questions and problems, Graphics Admin that takes care of the graphics on the server, LAT (Level Administration Team?) that makes the levels, which is how Graal is built up (were houses, roads, grass is built).
And as someone already said, you gotta meet their requirements, if you are really good at making graphics, you should send them in to some graphics administrator that then tell someone like SNK to hire you (for an example). Sometimes you may apply, but only sometimes.