One question: Is the Alt + Shift shortcut to change language a native/default shortcut, or you have set it manually ? And which OS ? I'm asking this because by default, I have set Alt + Shift + C as the shortcut to start Magic CSS. I believe that must also be conflicting for you.
I'll try to find some other shortcut key which is not commonly used for any other feature. I'll update here once I implement and deploy.
...... Update: Thanks for the response. Point noted. For proper discussion regarding this or anything else, you may head to https://github.com/webextensions/live-css-editor and create an issue there :-)
