Heh, I tired linux once. I even had my good friend, a linux master, come in to help me set it up. I forget what distro, as you say, it was. But it was supposed to be newbie friendly... 24h later we were still getting a weired error saying the HD was partitioned wrong. When we checked online we saw this particular error was unanswered by the devs for months. After that experience, my desire to set up another linux comp has been somewhat sour. Maybe you can suggest a form of linux that is newbie friendly AND works?
And the option you suggested, having my pc as gateway by using internet sharing... I read somewhere that can slow down the pc that connects to the internet. That's why I opted for a router (=more $).... but is that claim true?