No, that is literally the opposite. Fadeout on object destruction is the default. You have to manually specify for fade to be disabled. Whether your video card can render it properly is perhaps another issue entirely, but unrelated to what the game is actually doing.
Unless you use a stunt animation, the rotation of the die/dead animations are going to vary based on the creature's starting rotation. I would assume he is jumped to a waypoint for the final death shot, but that can still be a little inconsistent in terms of facing due to the way conversations work. So yes, it's probably going to vary a little, but it shouldn't do so in a significant manner. Especially since they are probably using static cameras which have a fixed position, so he needs to stay in the same spot to remain framed. That said, it's possible that TSLRCM changed things with the scene composition that might be a factor. I'm not sure.