Theoretically, but you're better off using Chicken of the VNC as a client. You can run it headless, but I don't have enough experience with it to call it a good idea or not. Even with a fast gigabit wired LAN, there's still a bit of a lag, so you don't want to do it as a primary workstation or something.
for the file sharing, in the Windows authentication dialog try adding the ip address of the machine to the username like this: MacIPAddress\YourMacUsername and the password for that OS X user. This is a bug in Windows or in OS X depending on who you ask, but that seems to help sometimes.