I'm guessing you mean where you have to visit the guard's friend? If so, you need a partner for this. One person goes up the castle (or whatever you call it) and pushes the lever and the person on the bottom goes in.
Secondary class is based solely on preference. There is no better secondary class for any type of character. It is all based on what kind of character you want to make. What do you plan to do with your character? What do you want him to do? Also, what do you mean by "Inner Gate"?
