It seems like there are a lot of quality-of-life features missing, like a kitchen/meeting area/mess hall/etc. Are there plans to introduce any of these?

It is not particularly clearly shown on the cutaway images and fully built out for the concept images but we have left space for a small living quarters area built around the bunk room exterior and in between the upper/lower turret entrance rooms. It's not the most luxurious ship, but then, warships often aren't. The combat-focused mission of the Hammerhead, along with size and performance considerations, also lead to a focus on combat features over comfort. That said, I'm sure there are Hammerhead crews that look rather jealously upon the Polaris' pool table.