can I stop someone from posting on my wall?

I think blocking an user only stops them from PMing you, not posting on your wall. However, Ты can change your settings so that only people you're a Фан of, или only yourself, can write on your wall.

Go to your Профиль and select Редактировать Profile. Scroll to the bottom of the page. You'll find a drop down box. It's set to "anyone" by default but Ты can change it to stop people from posting on your wall. Click Отправить to save your changes.

Yes and no. Blocking someone prevents them from commenting directly on your Стена but they can still do it if Ты post on any of the club walls. As I сказал(-а) on my last post--there's no surefire way to block people on this site. It's probably one of the least safe/secure sites I've ever been on in that way.

I'm not sure. I think Ты should just block the user and it will be enough.