What cultural faux pas should I try to avoid making in Leuven?

"In Leuven, it's considered rude to not greet shopkeepers, waitstaff, or other service workers when entering or leaving an establishment. It's also important to respect the local language, Dutch, even if most people speak English. Try to learn a few basic phrases. Belgians value punctuality, so it's considered disrespectful to be late for appointments or meetings. If you're invited to someone's home, it's customary to bring a gift, such as chocolates or flowers, but avoid chrysanthemums as they are associated with funerals. When dining, keep your hands on the table (but not your elbows), and wait for the host to start eating or drinking before you do. It's also considered impolite to leave food on your plate. Belgians are generally private people, so avoid asking personal questions unless you know the person well. Also, avoid discussing sensitive topics such as politics, religion, and language disputes between the Flemish and Walloon regions. In public places, keep your voice down and avoid drawing attention to yourself. Belgians are known for their modesty and discretion, so loud or boisterous behavior is generally frowned upon. Finally, tipping is not mandatory in Belgium as service charge is included in the bill. However, it's common to round up the bill to the nearest euro," said another expat in Leuven, Belgium.