These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Alternate Character Interpretation : In a way with Ruth's sexuality. As she appears attracted to women but as Susie described her watching her cousin undress it doesn't seem sexual. But her obsession with Susie and climbing in bed with Lindsey (even though in a platonic way) can both be read very much in certain ways. Her relations with Ray further complicate things as she kisses him to experiment and in one point gets alarmed she might have felt something. And then you know Susie uses her body to have sex with Ray. At that point a lot of people give up trying to classify Ruth at all.
Aluminum Christmas Trees: Apparently this comes up for some about unguarded cornfields being ways for kids to walk home from school. It's either normal or really weird depending on area.
Angst? What Angst?: Even taking into account the time-span between Susie's murder and Grandma Lynn's arrival at the house, she seems remarkably blase about the fact her eldest grandchild had been murdered.
Perhaps it's clearer in the novel, but the film's loose depiction of the timeline leaves open the weak possibility that she dealt with the initial shock of the event in a previous visit more immediately after the murder.
Grandma Lynn's equivalent visit in the novel is much, much later in the timeline than it is in the movie.
Bittersweet Ending: Naturally, since Susie is dead, and also Mr. Harvey is never caught by the police.
Arguably also undermining the point. As justice plays no real part in the family moving on. To many this would seem to be the major takeaway from the book. The lovely bones have grown without it and that is quite enough for the characters in the book to be happy.