Hi Alan,
Can't promise to answer all your questions, but lets see.
Freesco does not to my knowledge run Samba by default. It will probably be running a suite of TCP/IP utilites such as DHCP/DNS, Firewalling etc.
Incendently, sure you already know this, but they have a site
www.freesco.org
You can use direct IP printing with CUPS.
Samba emulates the SMB (Server Message Block) protocol which Microsoft utilises (amongst over things) to make shares/printers available subject to authentication.
I come from a Netware/MS background, but from what I've read, Samba is your best bet. You can use it to emulate a workgroup or domain and thus create authentication to shares etc.
I recommend using webmin for manipulating your samba setup. Not perfect but then graphical tools in Linux have a long way to go!
Kind Regards
Richard