[Andreas]

@Boofo
You can give this a try:

Hook: postbit_display_start

PHP Code:

if (!$post['visible'])
{
    if (!$this->cache['automodkeywords'])
    {
        $this->cache['automodkeywords'] = explode(',', $this->registry->options['automodkeywords']);
    }
    if (str_replace($this->cache['automodkeywords'], '', strtolower($post['pagetext'])) != strtolower($post['pagetext']))
    {
        $this->highlight =& $this->cache['automodkeywords'];
        $post['title'] = 'Automatically put under Moderation due to highlighted Keywords';
    }
} 


This should change the Post Title and highlight the Words.
To make it stand out further, you could overwrite the CSS Class here too, or set a $show Flag to check in postbit, or ...

@Martin
Brining Postcount into play is easy, just change the condition in the _presave Hooks to check $vbulletin->userinfo['posts']