Go into the group's control panel then to Modules, and Home Page Settings. I can't see into that group or it's control panel....... If you have a content block for forum topics, in the setting for that block there is an option for "Display Only Featured Content."
You could set one to only featured content, then you could put another underneath it that isn't featured content if you wanted to. Then you'll have your featured at the top. Be sure to name one featured so that you can tell them apart when you are looking at them in the control panel.
When you block a person, they can no longer invite you to a private message or post to your profile wall. Replies and comments they make will be collapsed/hidden by default. Finally, you'll never receive email notifications about content they create or likes they designate for your content.
Note: if you proceed, you will no longer be following .