Details in the movie that may have foreshadowed the plot *spoilers*

Awesome summary - I didn't pick up on any of the clues but I did wonder throughout the film why Detective Vick was so emotional and panicked when she was supposed to be the professional cop on the case. I was thinking it was just bad writing that the character wasn't more detached and professional. I also thought it was implausible that she would involve the Father so much like he was a fellow cop or something (up until he hit the wanna-be gangster at the cinema that is). It was a better film than I had expected. And you're right - the ending may have been cheesy but I liked seeing the screen saver changed to one of her and her Dad too.

Great observations! Also, the fact that Vick covered for her son's scheme to get money from the neighbors showed that she was overprotecting him.

Also right at the beginning of the movie when see first day of highschool photo, behind the dad and daughter it says catfish. Margot was catfished by Robbie.

On the blu-ray 'making of' bonus features they go through a huge amount of hints they deliberately put in the movie for fun. In fact at one point there is an internet comment on screen where someone literally gives away what actually happened to Margot, like word for word. But it's just one comment in a long list so you'd have to be a real eagle-eye to catch it.

I also found Vick's reaction to David going to the lake, that she was getting up and ready to meet him there in the middle of the night, was a bit odd. Because she had just previously yelled at him to stop doing things outside of the police investigation. TO me it felt like she needed to be there to handle what he might find and control the situation better, like how she noted they had already searched those two zones.