You can't customize shortcuts, the default ones are pretty bad - forcing you to use two hands to operate the inspector (on qwerty layout at least). I've given

You can't customize shortcuts, the default ones are pretty bad - forcing you to use two hands to operate the inspector (on qwerty layout at least). I've given up completely on Firefox as a developer's browser ... Chrome's dev tools are better, faster - they don't crash your browser or make it unusable like Firebug.