FonduemanVIII, There will certainly be opportunities for unsavoury things. But complains about them will be up to players ans NPCs. Some will make everything they can to stop them, other do nothing, others something in between. So piracy will be a thing (at some extent) and there will be NPC guards/lawmen and bounty hunters.
You CAN create a group of bandits out of peasants and do what you said and can be killed by those with more money then you (but just by those with more money ingame because after launch we will not be able to buy objects ingame, of any kind).
So, per overall, you CAN do anything you want. But everyone can have any reaction they choose to your actions. Still many details are not set yet.