Since I was worried that the current archive and search pages were creating duplicate content issues in Google, I updated the website's design to the veryplaintxt 4.0 theme. Since the website was running an older version of veryplaintxt before, this should not seem that much different.
Unlike before, I will not be heavily modifying the theme in order to get fluid width pages. Not only is it not worth the effect, but I think it actually decreases readability (if your browser window is too big).