Should I become a WoW seller? My thoughts and concerns.

I wanted to ask some questions about becoming a WoW services seller. I have most of my prices figured out and the type of services that I want to offer. But my main question was about security or just not getting in trouble pretty much. I notice many other people on sythe that have been providing a service for many months now or even years in some cases. Nothing seems to have happened to them. But I was asking one of my friends about this a few days ago and they told me that someone they knew also was a seller but eventually got banned for it. They even went on to say that this person was sued by blizzard too, so they had to return all of the money that was ever paid to them from other players.

Does this sort of thing happen often? Maybe this person was just careless and discussed the actual transactions inside the game chat. I'm not sure. I know that I only plan to discuss anything with people that I end up trading with on skype or other messengers anyways. However, I wanted to just hear other opinions from the community in general before I go any further. I guess when I hear stuff like this, I just get worried. I don't want to become a WoW seller if this can actually happen to me too. I have no intentions of scamming others. I just didn't think Blizzard would go so far as to sue someone. Do they really take it that far?

And the only other question I had was about using peoples accounts. Anytime I'm logging into someone's account to provide the service for them, is it possible that blizzard can track my IP and trace it all back to me? I'm thinking that could be how the other person might have got banned and sued. They didn't use their main account to provide the services. They just logged into other players accounts and did whatever was required on their characters. I might be wrong about that though. Just want to know more I suppose. I think I'm careful most of the time but I know I can't avoid actual IP trackers if they really try to hunt people down like that. I guess I just thought I could always login to other players accounts, provide the service, get paid, and discuss everything only in skype or other messengers beforehand, and that would be the end of it. I didn't think I could ever be discovered or punished if I kept my main account out of the equation or discussions.

I am cautious in general though, so maybe the risk of becoming a seller is too great if this is what can happen to someone else. Maybe you guys / girls get many threads about this, so I'll apologize in advance for asking similar questions. I just want to say that I am serious about becoming a seller though. I have my ads typed up and ready to go. I've spent a few weeks preparing too. But now I just don't know if I should proceed any longer. Maybe someone with more experience in this area can help me with these concerns. Share your opinions with me, good or bad. I will check this post often during the next few days, then I'll make a final decision about everything.