“That's too bad,” she sighed. “Cain't fix everythin’ wrong in this world.”

Element of Honesty notwithstanding, that seems harsh even Applejack standards.

Twilight frowned as she tried to find a nice way to call attention to her friend's still present trauma. “I mean are you… over Scootaloo yet?”

Scootaloo being dead really adds an element to this story that a lot of stories don't have. It also explains why Rainbow wanted to do something but it also makes Applejack's comment more callus even if it was a true statement.

Rainbow swallowed. “Um, she died attempting a dangerous stunt with the Washouts. I wasn't fast enough to save her. But it wasn't my fault,” she clarified defensively. “I tried to stop her.”

Some how, dying doesn't seem as bad as having done so during a stunt gone wrong while touring with a group called the Washouts.

Very interesting start.