One would expect some visual indications from engines not producing thrust. While the film makes it hard to see the nose attitude of the plane it was definitely going slow, the wing rolled left slightly and then rapidly to the right as the nose dropped. Cargo shift or, improper placement/weight and balance look more probable.
yes
I see that all but 1 of the 7 killed were from here in Michigan. Apparently the company is based at Willow run.