I hope you are aware that most inter european flights have no real class sections. (like LH, LX, ...) Only a free sight in the middle.
Besides that AB is a "normal" airline.
At the moment there is a massive restructuring ongoing and the new flight schedule is not fully loaded in the systems. So beware what you book.
You can see the new routes here (unfortunately only in German):
https://flights.airberlin.com/de-DE/die-neue-airberlin