You're right, but I'm not aware of any egregious salaries or bonuses. Both the president and all the chairmen are all professors, which generally means they are paid by their University, not Fraunhofer. The same applies to many directors of the individual institutes. The salaries for employees are based on "Tarifvertrag öffentlicher Dienst" ("labor agreement for public service",). Unless there's straight up fraud somewhere, there shouldn't be too much lining of pockets.