I am developing locally, so I can't provide a live URL. I think I found a workaround for this by creating a category called blog and nesting the other categories below it. I then made a custom blog template and it seems to work, with the exception of the breadcrumbs. I had to install Yoast's breadcrumb plugin to get them to work with subcategories correctly, as the breadcrumbs that came with the theme didn't seem to suport sub categories.
Thanks for the lovely theme - I am really enjoying working with it!