Another example of Jesus harming someone is when he sent Legion into the herd of pigs and they ran over a cliff and into the sea. Forget the problem of the nearest sea being 20 -odd miles away for a moment, but Jesus effectively took away the pig herder's source of income, what a nasty piece of work that Jesus character was.
I don't get the 20-mile thing. The story says he just got off a boat after crossing the sea of Galilee.
Even if the "country of the Gadarenes (Gergasenes)" would normally be taken to be somewhere 20 miles away, wouldn't it be safer to assume that whoever wrote that story was talking about the coast of the Sea of Galilee? Couldn't "country of the Gadarenes" be a reference to the people that inhabited that place, rather than a specific city or something?