There are so many great speculations going on here..some ring true to myself but some dont. I for one just cant fathom how daddy wouldnt know his child was missing?? I have to believe that fire went down after they "Dumped" things...so yepper..I have to agree these two were partners of this crime...It's always what goes on AFTER that sheds light on what really happened..
They can spin all they want..but and thats a big BUT..IF Zahra was found deceased, WHY NOT call 911 then?..why dismember her?, why dump her remains?, why bury her?, why dump mattress?? Why have a FIRE?? why create such drama?? Point is..THEY WERE HIDING SOMETHING!! and Yepper....They BOTH are equally culpible..I do hope and pray LE can connect all the dots!! These two people NEED to be held accountable for Zahra!!!!!
In answer to your great questions, I'd like to give my theory of what transpired. MOO, is that after arriving in the US AB, over time, became aware of EB's abuse of Zahra. For reasons I can't fathom he allowed it to go on. Additionally, I believe (forgive me for saying it) that AB engaged in and/or permitted sexual abuse of Zahra. With their frequent fighting (according to neighbors / family) and her abuse of the child, I can see EB turning him away from her bed and pointing him in Zahra's direction.
I don't believe Zahra was otherwise well-cared for either. IIRC (and please correct me if I'm wrong) a family member or friend stated rather early on that Zahra remained in her room most of the time except for the 10 or so minutes she was permitted to come out to eat.
Zahra became ill as a result of her mistreatment, was given no medical attention because that mistreatment would have been apparent, alerting authorities, and when she died as a result, AB dismembered the body to cover up evidence of abuse (both physical and sexual), disposed of it, and then disposed of / replaced the mattress in her bedroom. Upon hearing that Zahra's birth-mother had located them and knowing that they would have to produce the child if she'd contacted the local authorities, they concocted the fire, the ransom note and, eventually, AB's 911 call.
Based on the last time he says he saw Zahra, there would not have been time for EB to have killed her / dismembered the body / dug the hole within the hole and dumped the remains there and at the other sites in the short time-span without his notice or involvement. Surely, digging the hole would be a time consuming job... and dismemberment / clean up would have required a fair amount of time as well. This is merely my opinion / theory of what occurred. Hopefully, his own statements, behavior and the forensic evidence will bring AB to justice along with EB.
R.I.P. Zahra... Now you can run, play, jump, laugh to your heart's content.