as you mentioned yourself its a bad idea to do so. You have a good chance of "being killed by friendly fire".
Think about something like http://winscp.net/
if you want to access your files from windows,
or use Putty to do things by ssh.
The problem is not only an administrator with "low skill" (why is that guy an administrator?) but you are also asking for windows problems/exploits to hop on your RHEL6.
What could a low skilled administrator do by cut, copy or paste in wrong folder or file?
BTW even a defective mouse could do that.
What could a Trojan horse or virus do?
If still want to do so look if /etc/samba/smb.conf file has a line like:
invalid users = root
But again know that it is dangerous to remove or comment that.
A good advice: Do Backups at least daily!