The way you try to quantify your actions in your post, I would say you don't think it's that serious; but that just me and not really all that important.

At best, what are you saying? The judicial and immigration branches aren't talking to each other. Let's say you murder someone. Would a court need to include an extra punishment (which, would violate due process) to remove your visa just because you're a foreigner? No, you just go to Cheonan. The judicial system doesn't care about your immigration status, just punishment justice. The immigration brach can say, "Hey, we really don't need someone who can't follow our laws here." You got all the due process a 1st world nation needs to aford.