Well, I didnt get spoiled really, I just got told who the final boss was, I dont know why, besides EVERYONE knows giygas and pokey are the bad guys. I dont know anything bout' the story thought.
Yeah, Ness is kinda like Link in that aspect. Too bad someone spoiled Earthbound's ending for you. You should still play it and finish it though, it's a great game.
I love your Avatar, that little ness guy is always making me laugh with his Muteness