WordPress.org

Does this plugin add any database tables?

No.

Will this plugin work with Disqus/Intense Debate/js-kit?

This will only work with the default WordPress comments system.

If I disable javascript will it still work?

No. This plugin requires javascript to be enabled in the users browser for the comment to be accepted.

The checkbox doesn't appear in my comment form

The checkbox only appears for logged out users. If you're logged out, it only shows if you have javascript enabled. If you are logged out and have javascript enabled and it is still not showing then you need to have the comment form action active in your comments.php theme file

do_action('comment_form',$post->ID);

I am allowing trackbacks but I am being trackback spammed! what do I do?

You can download any of the number of trackback validation plugins which will check the trackback before allowing it or not.