Coincidentally, Samus' gunship in Metroid Prime's was actually a big design influence on the lower left sketch. Good observation, Nyton.
Luckily, those are designs I consider failed. Ideas I was trying out and didn't like the result, though I did pick up a few pointers here and there about what worked better and what didn't.
I figured watching a big of the design process could be interesting, at the very least.
In a talk I had with Doshii Jun, he shared to me that he thought visual elements I should keep from Miharu are those which encourage thinking that the ship is fast, like large tucked-in engines, an upswept shape, etc. Mating the rollbar with the rest of the hull was a good idea according to him because he figured it was one of the weaker points of the ship, but he didn't agree entirely with tucking back the wings and eliminating them by fusing them with Hoshi. He felt they could be kept, but made sturdier and less vulnerable at the base. (the comparison I made at the time was "turning a F-14 into a F-22")
Another debate I have with the hull geometry is how organic or mechanical I want the ship to look like. Organic forms lend themselves better to looking fast and aerodynamic, but looking more mechanical encourages mass and sit better with acknowledging the vessel as a light cruiser.
Another problem there is, if you look at the picture above, is that none of the 'brainstorming' I indulged myself in seemed to lead in a ship that was recognizable as Miharu, but improved. If you look at a Sakura-class and then set eye on a Plumeria-class gunship, that's immediately obvious. If I detract too far away from it, I might as well no longer call it Miharu, eh?