Fishcakes, I like that theme. I love that it is liquid/fluid layout, and works well on a skinny window or a wide screen. With 3 columns appearing to be set to a % each, even on a wide screen the line-length is not too long (for my eye).
If I use this theme, I would try to incorporate some navigation in the header, or, some of the typical sidebar content (like Categories) in the top left-column. For example, a 'zine using the Zine theme might want a link to their Photo Gallery, or Online Store, Contact, or About, near the top and above-the-fold, along with all that visible article content. (I noticed you provide space for sidebar-like links, at the bottom, under the content, a good place for the bulk of the links. Yet I need space for important links nearer the top.)
Another neat (but crowded?) variation would be Zine theme as a 4 column, with 1 left sidebar; and the sidebar would not be variable/fluid width, only the 3 content columns would.