Speaking of circular rooms and corridors...
Okay-here is an off-the-wall approach (no pun intended) that I just have to blurt out and get out of my mind. Circular corridors in the secondary hull? Sure. They could match the cross section going floor to floor from the main sensor dish to the hangar bay.
Now THAT would be a different approach... but I have too many other things I am pursuing to try to work that one out. Of course, the obvious problem would be the windows, which would now be full-height vertical.
Okay... I can focus again.