[TorpX]

2 torp detonations directly astern, yet the ship maintains ~6 knots until the stern goes fully under, I still hear prop rotation in proximity and on the hydro, as well as see the normal prop splash on the surface.

I don't know why this would happen, unless it is just a matter of the ship moving forward on the basis of it's momentum.

As far as crew evolutions, I can't help you there. However, most of the operation of the sub does not require crew. I know that sounds absurd, but it is true (unfortunately).