"Among other differences, for example, a German President is personally liable for the financial obligations of their company. If the company goes bankrupt, so does he."

Not really. Directors are not generally held liable for debts incurred by their companies in Germany. However, they can be held liable if they are found to be in breach of their duties as directors. Also, the onus of proof is reversed in some cases (e.g. the director needs to prove he wasn't in breach of his duty).