Change your smileys to another smiley pack or use your own smileys.
No, it just disables them. If you deactivate the plugin the WordPress default smileys will be back.
The best way to contribute is to spread the word, link to WP Smiley Switcher, blog about WP Smiley Switcher or give me feedback. All kinds of feedback are helpful to me. Suggestions and bug report are also welcome.