Some clarification on file URLs

Hi,

1. Can I describe the UNC path
"\\file_server\share\file.txt"

by "file://file_server/share/file.txt" ?

2. Is "file://10.213.123.23/c:/temp/file.txt" a valid file URL ?

3. Are "file:///c:/temp" and file:///c/temp (without the ":") equivalent ?

4. Is it right to say that the file URL "file:///outputFile" has meaning in Unix platform (/outputFile)
but has no defined meaning in Windows or Macintosh platforms (since there is no single root disk) ?

5. How should I describe Unix root directory : file:/// (3 "/") or file://// (4 "/") ?

Thanks in advance

Israel

BTW, I saw in http://lists.w3.org/Archives/Public/uri/2003May/0016.html that update for RFC 1738 is in progress. 
Was there any draft distributed, yet ?