I don't know why someone would be a smuggler. Let's say someone smuggles biomimetic gel or something...like, to the Ferengi. What do the Ferengi have that he can't replicate or whatever? I don't know, maybe he wants a dozen Ferengi servile wives. But to a guy who wanted that, I would say, "Is your holodeck broken?"
One crime I can understand is having oneself genetically enhanced. It isn't that I think it would be right, but I can understand why someone would feel like the risk was acceptable for them to try and become "better" in various ways.