PainGod

I think barbettes as discretely placed objects should be removed. Instead, any turret should have a checkbox or something similar to let the player determine whether they want it to be mounted on a barbette. This way we'd remove a bit of unnecessary clickfest as well as the maddening concept of barbette hardpoints.

The issue with this is, Diesels don't use boilers.

Why would it be in error? Unless you add armor to components that are responsible for causing the CoG shift towards one end or the other, adding mass that's evenly distributed would decrease pitch and roll moments as the net difference in mass for the bow and stern stays the same, but their overall weights increase. If you add armor to the middle, you get the same pitching moment, but it's affecting a larger mass, thereby reducing its overall effect.

Right now just about any damage even above the waterline has an impact on a ship's top speed, which I find doubtful.

They're not ingame yet. But yeah, internal machinery should be shifted within certain margins to retain the correct center of gravity.

I think you're all underestimating the effects of torpedoes due to the external factors of Pearl Harbor. Every ship that ended up settling to the ground would've been a hull loss at sea, and most of them would've sunk so fast as to make rescue of most of the crew almost impossible, especially under battle conditions. Oklahoma capsized and lost over a third of her crew while not going under the waves completely; both West Virginia and California settled on the ground with their main deck still above the waterline, and West Virginia was also evacuated when damage control efforts proved futile; and Nevada was beached to prevent her from sinking, thereby also eliminating one of the main causes for crew loss during WW2. Granted, a magazine hit and subsequent disintegration of a ship's structure would be immediately lethal, as can be seen from what happened to HMS Hood, USS Arizona and HMS Royal Oak.

Well, ideally all those options (especially the ones regarding visibility) would be added as separate modules to be built on top of your superstructure, kind of like you can place exhaust stacks on top of the tower on some models. There could also be incentive for mounting multiple gun directors, making your battery fire more accurate at range. Maybe even a tradeoff - a strong secondary battery or a precise main battery out to long range. The same could apply to the later radars, where mounting just one could mean your ship has a blindspot in its radar coverage straight astern.

I've been running into the issue of some ships sometimes taking inordinate amounts of punishment, hanging on with structure in the single digits for multiple salvos that cause significant damage, but the sections hit have already been completely holed so nothing happens. I would suggest introducing some sort of hull break mechanic that could come into play once a number of adjacent hull sections over no more than two stacks (5 or even all 6) have been completely destroyed. If that break happened amidships, the ship would sink, but if it was only the rearmost or foremost sections so destroyed, it could still survive at a massive penalty to its maneuverability and speed. Something similar to what I'm proposing actually happened to Lützow on her way back from Norway in WW2:

This is already possible at least for the main battery. I got 9 gun salvos off at long range in a Nelson-type setup.

I'm not really a fan of capital turrets mounted on capital turrets, but there is precedent for mounting small caliber AA guns on battleship turrets, especially late in the war.

One thing I'd like to see is dynamic turret ring mount diameter for turrets that mount different numbers of the same caliber tubes. For instance, back before WW2 there were plans to build the Scharnhorst class pocket battleships with twin 38 cm turrets, which was later changed to rearming them just so at the earliest opportunity by replacing their triple 28 cm mounts. Note that the main reason they weren't built with 38 cm guns was the fact the 28 cm turrets were readily available; 38 cm turrets would take years to develop, and mini moustache wanted capital ships as soon as possible to fulfill his political ideals. Another thing I'd like to see is the ability to connect the forward and rear towers with deck assemblies and integral mounting points for secondary batteries.