I don't know how long this will be available but take a look. "how to make that thing circled in red
go away:
http://imgur.com/SRigHSZNote that bookmarks is already opened up and does
not show Top Sites in the list, for removal.
The best that I could find was that in versions of Safari circa 2012 (and for a few years after?) there was a "Bookmarks" tab in Preferences for Safari. In that tab was a checkbox to show/hide "Favorites" in the tool bar. That specific tab no longer exists in Safari Preferences.
Other discussions indicate removing the icon is no longer possible, and goes on to say "so quit your griping". I'd say gripe all you want, but it is probably there to stay for now.