Crassmaster: 1.5 is the patch that 'changes' the game in to the Director's Cut.
Wrong, the 1.5 patch and the Director's cut patch are 2 separate independent patches. The director's cut patch is only needed if you have the US version of the game because the european version is already uncensored.
I finally finished DLing the game. The installer came in a rar file divided in several pieces but it wasn't password protected or anything. After unpacking the rar file in a different folder I run the setup and installed the game; it didn't ask for any code to unlock anything but it did install TAGES. The 1.5 patch removed the TAGES requirement so I uninstalled TAGES afterwards and installed the director's cut patch. The game can be registered at thewitcher.com site from the game launcher with the activation code I received by e-mail but AFAIK it is entirely optional.