rushing in single player is inherently difficult. many of the quests are mandatory, and there is really no way around that if you just play single player. you can join a multiplayer game and ask the people in the game to "rush" you ahead, but i don't think it is generally done very often. if you really want to get through the game as quickly as possible, i would suggest trying open Bnet - i'm guessing that you will find plenty of people there that are willing to help you out.