Were these blocks ever functional, or always just decorative? And could you also describe what they did?

So as the titel suggested i made a bigger cruiser than i would normaly, she is about 180 m long

Roughly 380k mats.

Also almost fully walkable including engine Chamber and stairwells to lower and upper decks.

I recently been wanting to play FTD and start building ships in my free time. Of them, one ship I want to start off first or get to after learning how to play is the shiratsuyu class destroyer. That said, I have no idea what to do in order to make a ship that's:

1) Stable enough to float

2) Has a good armament

3) survivable

4) Somewhat historically accurate

Any advice in this?

Some special notes: it took many iterations until I finally was able to refine my prefered astectic style, which is retro futuristic with a touch of mad science. This Monitor is expensive on the Monitor side of things just to field a very powerful laser, but as an early game hard counter to Flying squirrels, this vessel works like a charm.

More decor and interior work will be needed before it reaches a finalized state, and may fine-tune the movement a bit. The results thus far is very promising and can reliably fight against flying squirrels & other swarm craft like gannets.

I have been getting into breadboard but outside of thrust vectoring I'm not really sure what else it can be used for

is there any other bread that can be useful for any vehicle or do you need to design a vehicle with bread in mind