Gosh I'm still on the last thread and just realized this one will be closed before I finish up to reply. A few comments, from older stuff.
The theory that DC was the target: If she was, it would have been less risky for the bad guy to attack when JC was at work.
LE can get the IP address from Jayme's social media posts: Home computers seldom have a dedicated IP. It's all sorted out by DHCP.
Facebook requires it's users to be at least 13: She has posts going back to spring of 2013. I've known many friend's children who had accounts younger than 13. One close friend I talked to about it; the parent had the password so they could check all interactions, if the password was changed the account would go away, and by letting the child have the account they had a privilege that they could revoke if a punishment was called for.
The creepy guy story: Someone asked, "Did we know she went to Radar or did Radar just see her story online and go with it?" I saw it on social media a couple days earlier.
I think the theory about dad shot through the small window in the door makes sense. That would explain why relatives said the door was shot in, while LE said the door was kicked in. It could be bad guy(s) opened the storm door and pounded on the door, or started kicking the door. Dad came to the door, they shot him through the small window, then kicked the door in. Remember, LE says dad "had answered" the door, not "had opened" the door.
What were they doing for 20 minutes?: My theory. Terrible things were happening to mom. Jayme was restrained. 2nd perp? The chair? When bad guy(s) realized someone had made a 911 call, mom was finished off with a gunshot. Remember they said that the COD was gunshot, not that it was the only injuries. If it took them a while to determine the COD all the more reason to think there could have been other life-threatening injuries. Rage against mom seems like a good possibility. Why did they take Jayme? Maybe she had escaped, one person finished off mom, the other grabbed the kid and threw her in the trunk to deal with later.