Does the advised 30 year age limit also apply to the Composition section?
We are a bit more flexible when it comes to composition candidates, but candidates beyond the age of 35 are not often admitted.
Are there specific requirements concerning the compositions or the length of scores?
No, the only requirement is that the three compositions are representative for your work.
What is the content of the interview?
You will be interviewed by some members of the Composition teaching staff about your scores, your artistic and personal goals, your background, your motivation, your expectations, and other issues that you as a candidate and the teachers regard as being relevant.
What is the content of the theory exam, does it include a (complex) analysis?
The theory exam example as given here is a good example of what you may expect as theory entrance exam. It does not include a (complex) analysis. Only bachelor's candidates have to do the test.
Do you need to master an instrument?
Mastering one or more instruments will prove itself useful during your studies and while composing, but it is not an entrance requirement. From the first study year on you will follow piano lessons, obligatory as a secondary subject, to obtain a basic technique and knowledge in this instrument.