Neighbours from hell and trying to go my house?
Answers: Technically that isn't the neighbors from hell. One time in 3 years does not constitute an ongoing problem. I wouldn't mention it.
Edit: I don't believe nearby is a time period that you hold to tell them something like. It is up to the person buying the house to look for themselves. Also, what constitutes a problem for you may not be a problem for the different owner. I would still not mention it unless specifically asked.
Don't mention neighbors at all.
You just have to update what you know is wrong with your house.