Laws banning the mislabeling of products? A.k.a. label fraud?

There’s a semantic difference between “supporting mods” and “provide support for modded installations”. The former is fairly common and is what steam workshop is about and is what you are talking about.

The latter is basically unheard of (for what I hope are obvious reasons).

The OP is a bit ambiguous about which of the two or is.

People tend to underestimate the need for speaking German in Germany though. Depending on your location and social circle, you might not need much of it day to day. But certain administrative stuff definitely requires a decent understanding (and you really don’t want to misunderstand letters from the government).