Thats the issue though, its not the story but meta knowledge that is dictating. It totally breaks immersion... its like I am exploiting the game rather than following the story that the Dungeon Master is trying to tell.
Ye I completely agree with that. I never felt immersion in Act 3 apart from during individual quests (Cazador or Orin as Durge). But at least the meta knowledge lets you do whatever you want without being worried about failing a quest.