How can I find out who my friends have added and which communities they’ve joined?

You can follow your friends’ activity using the Updates tab (vk.com/feed?section=updates). When you open the tab, you’ll see a block of filters that will allow you to choose the kind of activities you want to see.

It’s important to know that privacy settings (vk.com/settings?act=privacy) apply to the Updates section as well. A page’s owner can edit the Which of my updates appear in my friends' news setting, which limits what appears in other users’ updates.
Your search for returned no results.
Try using other keywords, e.g.: "delete profile", "create chat".
Check your request for misprints.