Scholar theme page width change


How can I change the width of pages for the Scholar theme?
1. Lots to screens are wider these days and it seems like the pages could be made wider.
2. For many of the pages, there is nothing in the left side bar, how can I expand the width of the main area to use this space? see this page:

You will also see a couple of extra thin lines above the footer that it would be nice to remove.