I love "Knife in the Garden" and how it tells the story of the Precursors and Humanities golden age and ends with the sudden influence of the Darkness changing everything, but it doesn't really...get me in the mood to jump into things. Don't remove it, infact, it would be perfect if it played when you returned to orbit from an activity as a way to cap off a play session. Also, "Inner Light" should definitely become the main theme again since the Tower theme was switch back to the vanilla D2 one.