I haven't researched like extremely much, but the plugin SafariStand, completely fulfills the "immitation" of Activity window in former Safari versions, in a simple way. It was suggested here (by patrix), and from there you can find all the respective links. It's a freeware, by the way, and it works with ML(10.8.2).
you missed the one item (c), try this :
ALT+ duble click on the videoplayback — o-o- - -preferred- - -s .. you'll get a new window with the vido on it , play it with quick player then hit ALT+Enter .. the download will start .
#see a screnshot http://imgur.com/i8MzCc2