I encourage you to utilize a tool such as grepwin to search through the code for references for your 3rd party tools as this is the same method we'd use to look this all up.
I can tell you that: what=
is in: /scripts/showflat.inc.php & /templates/default/rss.tmpl
and values should be showthreaded/showflat and maybe showgallery
and that curl is not in v8.