I'm very excited for this game so I'll be glad to share feedback on it. Currently my main feedback is for the designer part of the game, so that's what I'll put here along with a question or two, starting with the latter and then moving to the former.
First, the teaser video kind of gave the impression we would put the hull together section by section when designing ships (which would give immense and practically endless customization combinations), which is quite different than adjusting preset hulls with a displacement slider to make them longer or shorter. Was this a misconception or is this coming in the future possibly?
Second, though possibly partly in connection with the first, will we see options to determine ship freeboard and the gun/turret visual styles different nations had, or will those styles be strictly tied to tech? Also what about further determining barbette thickness to an actual specified number and/or further specifying how much armor goes where? Or is this too much for the game?
Moving to feedback, I've come into encounters where it's impossible to build a ship with specific part combinations due to the limited hardpoint/mount system. In particular for funnels and superstrcture/towers, as well as trying to put 'secondary' guns (not the casemate guns) on anything but the 'modern battleship' scenario. In addition it doesn't currently seem possible to mount secondary gun turrets on a barbette, such as trying to model something after Yamato's forward and aft triple 155mm gun turrets above the main battery.
In addition and as mentioned by someone else somewhere, I've found it's impossible to recreate certain historical ships like the Brandenburg class for example. Though I also remember a response to that was a limitation with the different techs available in the Naval Academy scenarios or something of those lines.
That's all I've got right this moment, I'll be sure to give more feedback as I spend more time with the game and watch it's development.