Is acting out normal (non-forbidden) daydreams with specific actions considered part of the "work" mentioned in the Prophet's (peace be upon him) saying: "Indeed, Allah has forgiven my nation for what they inwardly converse about, as long as they do not act upon it or speak of it"?

Daydreaming and similar actions do not incur sin for a person. It is advisable not to indulge in them, for it is more fitting for a sensible person to strive in guarding their thoughts and to occupy themselves only with what benefits them in matters of their religion and worldly life.