Windows Server 2012 – Full support for case sensitive file and directory names?

The answer to both of your questions is No

Even though the file-system NTFS supports case-sensitivity for file and folder names.

But the Win32 subsystem does not support this. As explorer.exe, cmd.exe and the IIS FTP server are all Win32 applications, you wont be able to create files that only differ in their case.

You can use programs that are not Win32 based to create such files but then you can't deterministically say which of these files a Win32 based app would pick.

So unless you never use any Win32 programs that have to deal with files, you should not considered enabling it.

You would also confuse the hell out of your (Windows-)users.