These changes should not break anything, and if they do, then the markup behind the CSS needs to be fixed and not the css.

This change mostly targeted overqualified elements in the selectors which are bad for performance really. So things like div#bla should be #bla since its an ID there can only be one so whats with the div ... or img.sort should be .sort since what else is going to be in an image tag (and if class="sort" is used on non images, the markup should be fixed not the css to cover it up) ... or #footer_section ul li.copyright no need for the li since what else is inside of the ul that would have a class outside of the li .... stuff like that.

Anyway this was a branch I had left over when I was looking over the theme, use it if wanted, discard it otherwise ... just cleaning up my local dead branches