1. Turn off the sidebar globally. You can keep the index sidebar on but not show it on other pages. That way you retain the new look and feel of PP8.
2. You can set your medium width to a slightly lower threshold and rebuild mediums if turning off the global sidebar is not enough yet it looks like that might be all you need to do.
How do I rebuild the images? I have it constrained to 1024 width I think, it's odd that this one only shows 960 width but blows out the side but the 1024 images are OK.