You don’t need to register a business for a bit of side money. Even in Germany, you don’t need to register as “eingetragener Kaufmann” unless it’s, you know, actually a proper side business and ticks some criteria.
Going down that road, there’s heaps of people doing consulting as sole proprietor (or e.K. In Germany) without getting sued or stuck in tax hell
I think you’re looking at things a bit too pessimistic here