[Kakurin]

Originally Posted by AC-Phoenix

My point is that there must have been more than just 4 underwater hits from long range in the first place with 2800 shells fired.
Less than 1 % actually hitting sounds unlikely considering how her course was pretty much predictable.

The British were too close for underwater hits to happen. Most of the shelling happened from a distance of well below 10 km. The flat trajectory of the shells would've led them to ricochet off the surface of the water and fly into the upper hull or superstructure.

And you have to clarify the number of shells. The number 2800 (of which about 300-400 actually hit) doesn't tell that much. More relevant are how many were fired from which guns? KGV fired 660 5.25" shells and Rodney 716 6" ones. Those can be taken completely out of the equation since they are only capable of damaging the unprotected upperworks. Likewise the 781 8" shells from Dorsetshire and Norfolk can be taken out of the equation. They concentrated on the superstructure of Bismarck. So actually relevant for the hull are only the 339 14" ones from KGV and the 380 16" ones from Rodney.

Additionally the British somewhat hindered their own efforts by bombarding both sides of the ship. So the floodings that occured offset each other. Note the difference to the American approch against Yamato where they only targeted the port side to force her to capsize.

In 1942 Prinz Eugen was also torpedoed in the stern, which subsequently collapsed. This prompted a strengthening of the stern structures on all German capital ships.

Ah yes, this. But again one has to be careful here. The stern structure problems on the German ships were a result of the welding technique used to attach the stern to the hull. So it's a structural problem. It is debatable how much a strengthening would've actually helped.

First Lütjens decision to not open fire or even shoot back., second his decision to make the maneuver that took out her rudder.

I don't know what you are blaming him for the rudder. This was a combination of inadequate protection of the rudder area and design choices.