What was the point of including the space pirates, other than just showing that humans had taken their petty squabbles off world? Was it just reshoots to add some action?

What was the point of Donald Sutherland's character, who just leaves the movie 5 minutes after entering it, never returns and does little of consequence?

Ruth Negga's character was completely pointless, other than to tell Roy how to board the rocket and confirm that Tommy Lee Jones had gone insane and murdered his crew.

If the space agency already knew the surges were coming from Tommy Lee Jones' ship, and where just planning to nuke it anyway, what was the point of getting Roy to send the message at all?

Why did the space agency assume that Clifford would know what his son's voice sounded like 30 years later? If they needed to send a message, couldn't they have just had somebody impersonate him?

So apparently Roy is still employed by the agency even after disobeying orders and causing the deaths of several other astronauts?