Those gouge marks in the runway surface (video 3) look to be 1 or 2 inches deep which means the aircraft hit pretty damn hard. The marks also evidence a touchdown travelling at an angle of 30deg across the runway centreline so the approach was very far from being stable. The debris field appears to indicate airframe break-up started BEFORE the main body went down the ravine.
Considering that the cloud ceiling was 500' above the runway it is difficult to imagine how a stable approach (even one that busted minimums) could have been mishandled enough to result in crossing the runway at 30 degrees with such a rate of descent. It is quite possible this aircraft was stalled at impact.