All the changes seem reasonable. There's just one small comment I added. https://codereview.adblockplus.org/29366570/diff/29366607/chrome/content/firstrun/fancybox/jquery.fancybox-1.3.4.css File chrome/content/firstrun/fancybox/jquery.fancybox-1.3.4.css ...
https://codereview.adblockplus.org/29366570/diff/29366607/chrome/content/firstrun/index.html File chrome/content/firstrun/index.html (right): https://codereview.adblockplus.org/29366570/diff/29366607/chrome/content/firstrun/index.html#newcode107 chrome/content/firstrun/index.html:107: Open-source software released under <a href="http://www.mozilla.org/MPL/1.1/">Mozilla Public License</a> On ...