Spirited Away seems to be about the Chihiro-mom-dad unit developing an imbalance, manifesting as Chihiro's fear. When they're pulled into the spirit world, Chihiro separates from her parents, breaking that identity unit apart. Since the story is from her perspective, her parents no longer serve a useful role, and so are reduced to consumable resource (livestock) - the default job available to all entities.
The main character stabilizes (by consuming food from the spirit world), and in doing so externalizes her imbalance as No-Face: a nascent and imbalanced spirit with almost no form, having the most rudimentary of masks. This reveals the apparent hierarchy of the spirit world: spirits like the radish god, who perform essential functions in the physical world (growing food, embodying rivers), have achieved such coherence that they don't require jobs in the spirit world to maintain their form. Instead, they come to the bathhouse as honored guests, where the spirit world serves them, nourishing and replenishing them for their service in the physical world. Those spirits without physical-world functions (or those who have lost them, like Haku whose river was filled in) must work within the spirit world to maintain coherence, or risk becoming formless like No-Face.
No-Face thrashes until Sen gets involved - it seems that No-Face can't reach stability without Sen's help. Through a series of job assignments/completions, Sen arrives at a place where No-Face is welcomed and given a job (with Zeniba). This stabilizes No-Face, arresting Sen's descent down the narrative stack (as it were), allowing Sen to step *back up* the narrative stack until she reaches the point of Chihiro's identity dissolution. She identifies those spirits serving as Chihiro's parents (or rather, identifies their definite absence).
It seems that the system doesn't trust its *load* to an arrangement until the component parts of the arrangement mutually acknowledge shared understanding. Sen must sign a contract to confirm her role; Yubaba must realize that Boh has been replaced before the illusions are broken; Sen and Haku must recognize each other for the spell binding Haku to break; Yubaba must confirm Sen's choice about her parents ("Are you sure none of these are your parents?") before the composite identity of Chihiro-mom-dad is restored to functionality.
The film ends where it began, with one change: Chihiro's fear has been given *a job*. Her dad muses: "A new school and a new home, it is a bit scary…" Chihiro confirms: "I think I can handle it."
All of this feels to me like an agent traversing a fractal system of identity and service - and … healing it? maintaining it? And the nature of the agents themselves seems somewhat fluid: note that Sen recognizes Haku, having encountered Haku as the Kohaku river in the physical world. This would have been decades prior, so it would have been via an identity other than Chihiro.