Add: “3. The ability to replace the Tor Browser window icon.” 2 and 3 are not of same approach as explained here: Change my Tor Browser icon to hide it's Tor Browser
Most of this ability already exists! By default Tor Browser looks the same as Firefox when only two buttons of sheild and brush are removed (which can be removed easily by right-click). Only Tor icon next to “New Tab”, “.onion available” button and the icon of Tor Browser window itself are Tor-specfic and need to be changed. It should be easy.