I would do the following:
1. Add some space between the recent posts items
2. Use smaller tweet and like box sizes
3. Add vertical padding between post headlines, dates and post content
4. Reduce the size of the nav text
5. Go through and add vertical padding anywhere that spacing seems tight. For example, the about us image and opening paragraph. The top of the social sharing div and the content.
6. Add vertical padding to the footer copyright.
Aside from those small spacing items, it’s a nice design.