said by aurgathor:
Since I have a wired network behind a separate PC acting as a firewall/router (Freesco) that either requires physical access to my network, or a beyond average hacking skill.
Sure, but that's not the way it works, and a good thing too, since it would mean that any firewall failure would result in total access to all computers.
Basically, any standalone computer trusts only those usernames that it defines. If you add the computer to a domain, then it will also trust those usernames that the domain controller defines.