There must be a clear understanding what Newsfeed is in the first place.
Newsfeed is a collector type of plugin: it gather all kind of items passed to it by other plugin. As an output you will see a newsfeed widget. Newsfeed will automatically list all actions of your site such as somebody registering, commenting, adding content and liking. As site admin you can not control this unless you monitor newsfeed daily.
If you would like to have something SIMILAR to Newsfeed where you will be posting something yourself so that your landing page gives a good first impression you need to hide newsfeed from guest users and use WALL widget instead.
Wall widget is a "grand-parent" of Newsfeed plugin. Wall widget is simple - you get only what you post. No additional sitewide actions will be listed. And again you can make this widget visible only to users of certain user role, thus you can limit who can post into wall.
It's interesting but not really... what we want.
Did you mention that Instagram has a "explore" page or twitter's recommend box? That's what we are talking about.
We neither want to control the newsfeed nor anonymous it.
Just a list of information, like in the main page Newsfeed could only display the feeds that have greater that 10 likes or such. That could improve the information quality significantly.