All of this is false according to history. There is no precedence for any of these proposed outcomes.
MapleStory's market has performed perfectly fine over the countless amount of "game breaking" exploits. This includes generation of mesos in the trillions, duplication of many rare items and much more.
Packets are not risky at all, this has been gone over countless times. Furthermore, the host is the server.
There existed many "NX" exploits in which NX items/effects could be obtained. Nothing bad has ever happened, no jail time and no law suits. Nexon is really going to come after you for "stealing" (implications that Nexon is losing profits; were you ever really going to spend money on NX, a virtual currency that is worth nothing seeing as it can be generated with a click of a button?) 20 dollars worth of merchandise. The time wasted and the money spent on litigation is worth every penny that Nexon will milk from you. They have enough money to throw around already, why not go after a few kids?