1. This is so impractical that I switched to opera as my main browser where it is a press on F12 and a click to enable/disable js
2. When your product does such a bad job that it has to rely on a third party extension to provide functionality to users, maybe you should consider the possibility that you should include these features in your product.
2. NoScript does a much better job than poking at the Firefox preferences every time you want to toggle JavaScript.
Are you seriously going to fall on your sword and stick with Chrome over this?