I don't like all the features you turn off, and most seem to offer no security benefit.<p>Turning off pdf.js is arguably a security downgrade, since it is a sandboxed javascript reader and any other means of reading pdfs will not be sandboxed.<p>As for additions, CanvasBlocker is important to prevent browser fingerprinting and doesn't interfere with your browsing experience once you turn off notifications.<p>Ideally, Firefox's password management ought to be turned off and you should instead use KeePass (and the PassIFox firefox addon).<p>I would also recommend turning on e10s since it sandboxes a lot of stuff in processes, and is fairly stable now.