I had a router/hardware firewall at my old place because we had 2 computers. At my new place, it's just me here. As long as I have personal file sharing turned off, I should be all set right? I don't need to install the firewall? In the Sharing pane, there's an option for Firewall, which is currently off. What are the advantages of turning it on? If I do turn it on, will it interfere with my usage of Acquisition, AIM, DC, etc?