Is it possible to make available all shortcode in visual editor?
Most of the theme have similar feature with their branding icons and it is most commonly used feature i think.
WordPress have a function "add_shortcode" to declare new shortcode and it accept 2 param like following:
add_shortcode( $tag , $func );
1. Now i think, it can have 3rd param for custom icon function/file url/css class etc.
2. In wordpress, there should be a method to find available shortcodes.
3. When it have 3rd param, shortcode will be available in visual editor with custom icon. If third param is not available then show default icon.
4. When click on a shortcode icon, add some markup for shortcode in visual editor.
May be following plugin will help you to understand: http://wordpress.org/plugins/shortcodes-ultimate/