Comment Section and Leave a Reply Box Not Centred

Hi there, I noticed that my comment box, and leave a reply section in posts are skewed to the left. If I activate the sidebar in the post, it also skews to the left, even if I specify the side-bar to be on the right-side in the "Edit Post" section. Here is my website: http://monkandmarvel.ca/?p=1 1) Could you please tell me how I can have the side-bar show on the right side of the post (within the box)? 2) Could you please tell me how to centre the "Comments" and "Leave a Reply" sections on the post? Thanks in advance, Jaclyn