Exactly. The totem is "an elegant solution for keeping track of reality." And reality is the garden on the cliff, something emphasized not only by the comparison of life to a dream and dreamers to "figments" and "shades", but much more directly in such lines as Cobb's father urging his son to "come back to reality" when none of the characters are even dreaming.

We know Cobb doesn't need his totem by the end, because his rejection of Mal at the climax is an expression of faith. To understand the implicit alternative, look to the parallel heist sequence which opens the film. There we had a very different Cobb place his faith in the "reality" of Mal when he lowered himself out the window above a fatal fall. Nolan emphasizes that this is the wrong decision by showing us Cobb's immediate (biblical) fall, blasphemy and then betrayal and loss. Death destroys the world by water as foreshadowed in the parable that opens the film.

At the end of the film the logic of this sequence reverses. Cobb resists Mal's temptation to stay with her in limbo. He rejects her for the first time ever, telling Mal she is not "real" where even moments before he was expressing lingering doubts to Ariadne ("how can you know"). And whereas his lack of faith had previously led to his defeat, here his expression of it leads directly to Fischer's symbolic reconciliation with his father. And while the film presents another death sequence as required by Matthew 7.24, this is but prelude to a heaven sequence that breaks the endlessly circular logic of the dream world / penrose staircase. The rules are violated because they no longer apply: Cobb is free of the maze.