It’s such a perfect adaptation, it’s easily the best film adaptation of Peter Pan by FAR. It takes all of the most interesting aspects of the book and amplifies it, and what changes it makes to the source material exist to better serve the nuance and themes of the source material.
And yes, Peter does kill Lost Boys in the book. This is implied multiple times.
“The boys on the island vary, of course, in numbers, according as they get killed and so on; and when they seem to be growing up, which is against the rules, Peter thins them out.”
“He had seen many adventures since home, but he had forgotten them all. One adventure was enjoyably like another. If you killed an adventurer you had to sit down right there and look as if you had not done it; and if you went out you would find a body. It was an unwritten law of the Neverland that you never did anything unless you were entirely in the mood for it, and Peter was rarely in the mood for remembering.”
The horror of Peter is that he has an internal clock that forces him to forget everything he does, so he will never learn, and therefore never grow up. The novel showcases this more brutally than the film (because the film deleted final scenes), where only a year later Peter has already completely forgotten about Hook and Tinker Bell etc. And eventually, he forgets Wendy too, and doesn’t come back until decades later and is horrified to find Wendy is an adult with a child, now.
He’s confused as to how this could be, because nothing really exists to him, not even time itself. That’s why it’s so perfect when Peter asks Wendy in the film: “Wendy? It’s all make believe, isn’t it?” about them playing House etc. Everything is a game to Peter. That is the horror of eternal youth. The carelessness for which a child can behave and think.
And the tragedy of Peter is that he was a traumatized boy that ran away himself. He did return to his parents, only to find that his window was barred shut and another baby was in his crib.
“I thought she would stand at the window for ever and ever with her arms out for me, so I stayed away for moons and moons and moons, and then I flew back; but the window was barred, for mother had forgotten all about me, and there was another little boy sleeping in my bed.”
In the book, this story Peter tells Wendy terrifies her so much that she wants to go home immediately. Peter flies ahead of them and attempts to bar their window shut, because he wants Wendy to stay and to keep her for himself. That’s why it’s so emotional to me that they depict this trauma in this film by having Peter go to the Darling home, where he tries to force their window shut. He says “we can’t both have her, lady” to Wendy’s mother, and then tries to hold the window closed while their mother and father try to open it for them. I also really enjoy the alterations they made to the final battle from the book. They really play on Peter’s trauma and tragedy more than the book does in this final act. The book keeps it mostly subtextual and implied. The final battle in the book is not nearly as gripping as this film’s version. But the change here is a good thing!
Sorry for yapping on your post OP, I just love this movie and I love Peter Pan!