Yeah you can insert a shortcode on the forum index page using some hooks that bbPress provides.
bbp_template_after_forums_loop
Here is a code snippet that will do what you are looking for though.
For the freshness link it should link to whatever was the last activity, with that either being a reply or a topic created. If you want you can filter the forum freshness link to just show topics I guess. The filter is bbp_get_forum_freshness_link