anything is possible, it could also disintegrate midflight for whatever reason (bomb, factory/maintenance error), difficult to fly without wings for instance or with plane broken into two pieces
Based on what? As horrific as it might be it wouldn't surprise me if passengers were conscious all the way down. Even if oxygen masks didn't deploy or work, at 26,000 feet you have a few minutes of useful consciousness after rapid decompression [1]. Combined with the fact that the plane would be rapidly descending.
Nonsense. G forces are changes in speed or direction, those were pretty mild based on what we know right now, freefall or powered flight into terrain does not give huge G forces until impact.
You can't really rule that out a-priori any more and there are a couple where we likely will never know for sure.