Regarding your footnote [1], it wasn't entirely an excuse. Most of the new things people hated in the movie were from Douglas Adams himself (he did almost all of the film's many, many drafts), because he never could tell the story the same way twice. You can almost tell there was a telephone effect in Douglas Adams writing, revising, rewriting his own drafts so many times for the whims of Hollywood executives. The interesting bit of final irony being that when Douglas Adams passed Hollywood passed it off to British directors that didn't meddle much further with the final draft beyond what happens naturally when you cast it and storyboard it.