auth.dll, authad.dll, authlogonuser.dll, ldapauth.dll, ldapauth9x.dll, ldapauthnt4.dll are used for the "old" mslogon.
The new mslogon currently uses authSSP.dll and SecurityEditor.dll.
vncdrv.sys and vncdrv.inf are indeed for the video driver and are not needed if you won't install the video driver.
This applies also to vncdrv.dll, vnchelp.dll and vnccom.sys.