I don't know, I like how the primaries have a single turret barrel - after all they have a single projectile. Perhaps try and work on a single barrel turret? Core-ify it with some power tubes or something.
you know the center bean on which the turret barrels are connected to? try thickening them, and then i think it'll be good to go. the textures are distorted/blurry, so i suggest trying to fix those. if you look at the base, certain faces have that black/yellow pattern going left to right, certain faces have it opposite. i suggest turning them to be facing one way only.
Actually, I would suggest that the number of guns on the turret is corresponding to the rate of fire. At least, transport turrets seem to be this way. Also, why not make a missile turret?
I don't eally et what you're trying to say about thickening some part Gurj, but the stripes go same way on both sides, since all side parts are mirrored.