Allows you easily to add custom Quicktags to the post editor.
Yes. You can add a self-closing Quicktag (like <hr />) by leaving "End Tag(s)" empty.
Yes, you can. There's two ways:
Yes. Since 1.2 you can change the order of the tags. Just roll over the number on the left and you should to able to drag 'n' drop the rows.
Yes. Version 1.1 introduced the import and export feature.
On the options page, click the "Export Quicktags" title. That should give you a textarea with some strange looking code. You should copy/save that so you can use it to import on another site.
To find the import feature, click on the "Import Quicktags" on the same page. Paste the copied code into the textarea and click "Import Quicktags".
The Quicktags should now be imported and it doesn't overwrite the old ones.