Chop
It is more satisfying to improve your ship yourselves, so let me first give you some tips:
You are good on your way, but:
-Try to use compartments to make your ship more efficient. look at this:

Just add fire extinquishers here, and seal it off: improved output of bullet-hell!
-Remove useless corridors. You can use structur eto fill the empty hole if you want.
-Lower the amount of electrobolts, less will do almost as well and you can add some more damaging weapons instead, like lasers.
-One sensor array is as good as four.
-Where are your point-defenses? Missiles will be much les sof a threat if you use them.
-Add shields to protect the missile launchers on the "head".
-Place Command rooms in the sid eparts of the ship, incase of them being cut off they will flank your opponent.
-Remove doors: To many doors make your ship more expensive, and most don't get used, look at this madness:

-Hide the railgun deeper in your ship, now you can just focus fire and destroy it easily.
Also:
-Use wedges to improve the shape, take a look at the neck, which could look smoother with them. We are not playing a blocky game like minecraft here!
-After you optimised your ship, it will not only be more effective, it will also be cheaper. Because less crew, doors and corridors will be used.
Good luck!
If you want an example, look at how I improved a very old ship of mine:
Before:

After:

Need more tips & tricks? Look here: https://forum.cosmoteer.net/d/4578-dos-and-don-ts-for-building