Cute idea. Needs a better example document to really be judged properly (for example, this document has a far too many large and imposing headings), but in any case, some comments: Would be better with less leading, a smaller text size, smaller left margin, and more characters per line. This current version has a text block more like a newspaper column width than a book, and the large type and unnecessarily generous…
Totally agree. At least with italics, you can use CSS to instruct the browser to not create fake italics using the font-synthesis property: https://developer.mozilla.org/en-US/docs/Web/CSS/font-synthe....
Also, setting the document font size to 11px is a bad idea for a whole lot of accessibility reasons. The current best practice is to leave the global font size at 100%, which in most browsers is 16px by default.
This allows users to scale the type up (or down) as needed, unlike various versions of IE which won’t allow this if the base font-size is set in pixels. This allows the media queries to work correctly, since they always assume 1em = 16px. Resizing the fonts should be done in rems, with pixels as a fallback for non-supporting browsers.