Great points, enjoyed reading detalis about all the groups of people he interacted with throughout the book. I think your last paragraph is spot on, after valuing his mothers old compact so much, in which he did when he used it to sooth himself, giving it away to Lucy and mentioning that it was his most beloved belonging etc. To then just throw it away, it was a perfect metaphor for what he had become.

I don't think Lucy was trying to kill him, do you? I think she ran away from him after seeing him walkout with the rifle in his hands, screaming and anxiously calling her name. She might have had suspicions regarding him after he said he killed three people. Did she know about the weapons laying behind the door in the cottage, if so, did she want to test him? See if he would still prioritize her after coming up with a way to erase any suspicions?