Your script is overall well-written and entertaining, with a good amount of humor and charm, reminiscent of Douglas Adams' style. However, there are some areas that could use improvement to better match Adams' tone and content. Here are some suggestions:

1. Absurdity and Satire: Douglas Adams' work is often characterized by a high degree of absurdity, irony, and satire. While your script certainly has some absurd elements, it could benefit from a bit more of these. For instance, the G'largh Stone's significance and powers could be presented in a more over-the-top and satirical way, perhaps with a commentary on how societies obsess over such artifacts.
2. Randomness and Unexpectedness: Adams' work is known for its unpredictability, with random events occurring out of the blue. Your script could incorporate a few more unexpected and seemingly irrelevant incidents that later turn out to be significant, or at least humorously inconsequential.
3. Philosophical and Existential Themes: Hitchhiker's Guide often delves into philosophical and existential themes, usually with a humorous twist. Marvin, the Paranoid Android, is a good vehicle for this, and while you have included Marvin, his dialogue could be used more effectively to highlight these themes.
4. Complexity of Plot: The plot could be a bit more convoluted, with more false leads and red herrings, to create the kind of convoluted plotlines that are common in Adams' work.
5. Use of Guide Entries: The Guide entries in Adams' work often serve as humorous asides that offer social commentary, or they introduce absurd concepts. You could incorporate more of these and ensure they have a punchy, comedic tone.
6. Characterization: Characters in Adams' works often have distinct and exaggerated personalities. Zaphod, for instance, is more than just cunning - he's outlandishly egotistical and over-the-top. Try to amplify these characteristics in your characters' dialogue and actions.
7. Dialogue: Adams had a knack for sharp, witty dialogue. Try to inject more humor into the characters' interactions.
8. Narrative Voice: The narrator in Adams' work often has a dry, humorous tone and offers asides, commentary, and witty observations. Try to incorporate more of this into the narrator's lines.
9. Absurd Similes and Metaphors: Adams frequently used outrageous metaphors and similes. Incorporate more of these into your descriptions and dialogue.
10. Engaging with the Absurdity of Life: One of the defining features of Adams' work is his engagement with the absurdity of life and the universe. Try to highlight this more in your script, perhaps through the reactions of Arthur or the situations he finds himself in.

Remember, Adams' work is unique, and replicating it exactly is both challenging and may not serve your own creative voice. These suggestions are to help bring your script closer to Adams' style while maintaining your originality.