Hello,
 Anwers: 
1) I did not configure a password, so normally i get the login screen and then automatic the desktop screen.
    but now with classic shell I only get a short time see the W8 icon (blue blocks and circling points) then 
    immediately a black screen. 
2)  Yes, it is the black screen. 
3)  After de-installation of the Radeon driver Windows works fine, it comes up in desktop mode. 
	but with the W8 startbutton I can switch between desktop and metro screen. 
	The resolution due to limation of the Microsoft basic driver is reduced. 
	But the Classic Shell works fine and I don't get the black screen. 
4)  I normally use Ctrl+Shift+
Del to get the taskmanager, but also this does not appear with Classic Shell active. 
Btw.  I was just searching the Internet I found other W8 button tools and tried these as alternative and test
- Windows 8 Stardock Start8 v103 has exactly the same problem
- Startmenu 8  see 
http://www.iobit.com/iobitstartmenu8.php. does not show the problem.  
But I like and prefer the Classic Shell because it offers much more functions to tune the behaviour.  
Cheers Jaap   
I hope this helps.