After some query, function and class debugging, I now realize that bbpress runs on post_types and a heavily modified wp_query calls and a bunch of (largely undocumented) functions and classes. Most of the magic happens in a Loop that is different depending on what you want to show.
Looking at the widgets calls has been tremendously helpful in successfully achieving what I wanted to do.
I managed to find a function/class list with comments at http://phpdoc.ftwr.co.uk/bbpress-plugin/ that was also very helpful.
I leave this for reference to others, hope it can help someone else.