1. Sections removes the entry header where the title is displayed. Where would you want the title to be displayed? Above the first section or over the featured image ( see point 2 )
2. You can see a full with Featured Image using the Header Element, it also allows you to add the Post Title using the {{post_title}} template tag:
thanks but not exactly what I was thinking; I just want to be able to show the title below the featured image and want the featured to be 100% according to browser window;