A Few Requests

I am using the style "content to the left" with the sidebar on the right. I feel like the whole site is squished in the middle of the page, and the margins on both the left and right side are far too big. How could I lessen the page margins as a whole, globally? Also seeing as I am the only person posting to the blog, I feel the "Posted on DD/MM/YYYY by xxxxx" is unecessary, how can I alter all occurences of it to just say "Posted on DD/MM/YYYY"? I would also like to remove the "Edit" button everywhere on the site, seeing as I manage the post content from inside Wordpress itself. Other than that, great theme. Thanks. Site URL: iamtpage.com