Yes, I think that if you're character is a punk or an anarchist, you can RP it that way: bring the ulbers, insult people, steal dropped items, etc., etc...
BUT
"My character is Evil" is not an excuse to bother or harass other players nor does it entitle you to take advantage of loopholes in game mechanics or ignore that there are laws in Yliakum. If you pick up an item that was on the ground or if you steal it by pretending you are going to repair it, you're taking advantage of the fact that your victim cannot do anything to you. They can kill you a thousand times and still not get it back and if they reported you, GMs would tell them not to do that again and that it was their fault (partly true). The point is: you can do it that way but there is no need. You can return the item as an OOC thing but RP that you still have it. You are still a thief, they will talk to you like one. I think the best way would be to give them a chance to get it back, either by dueling or rolling the dice or whatever. Yes, the victims are guilty of trusting too much but IRL we're not able to walk through people and we are not unable to loot a dead enemy. So, if you steal something and then run through your victim (when they would be trying to hold you back) and then die in the duel or, even worse, decline the challenge, you are taking advantage of game mechanics and that has nothing to do with being evil or RP.
Both good and evil characters have to be consistent. I agree with Maerghaine that if you're good you shouldn't be comfortable with serial killers or dwarfslayers camping the same rogue or chilling next to you in the pub and RP that way. It doesn't mean report them! It means RP it. And evil characters have to be consistent too. If A.I. was implemented for NPCs to react to crimes, you would think twice before attacking anyone in the city or stealing from them. But that would limit RP a great deal so it is up to us to determine the boundaries. You want to be a murderer? You'll need someone to accept your challenge. They will RP with you. You wanna be a thief? Then RP it. Negotiate OOC the rules of engagement so that the outcome is open so either party could win. Yes, if you trick people into giving you a certain item you're totally IC, keep doing that but you should include a way to even the odds because that would keep your RP completely IC, no loopholes, no exploits.