ARD-Hauptstadtstudio

The provided news articles do not mention "ARD-Hauptstadtstudio." Therefore, it is impossible to provide a description of who or what they are, why they are newsworthy, recent events or developments related to them, or their current relevance or significance based on the given information. The articles cover various political and social issues in Germany, including proposed changes to marriage tax laws, investigations into Bundeswehr soldiers, debates on immigration and violence, calls for a windfall tax on oil companies, and the arrest of suspected Russian spies. However, none of these topics are directly linked to or involve the ARD-Hauptstadtstudio.