Which is exactly why I've suggested swapping control of the weapon, like with the T1-B, where the hard-to-aim missile pod is given to the driver of the tank so that he can compensate for its inability to aim to the left and right by turning the tank. Another example is the AT-ST, in which the weaker of the laser weapons (the one on the side of the head) is given to... the driver, who has the ability to directly control the turning of the head.
Likewise, the hard-to-aim weapon of the Firehawke should be in the hands of the person driving the Firehawke. It'd make both the antipersonnel gun and the main weapon a thousand times more effective (the latter would be more effective because the gunner can concentrate 100% on using it as he doesn't also have to keep checking to see where the tank is going so he doesn't run into something), and it'd also be "fair" to the T1-B, which also requires a crew of two, and it'd strongly discourage lone-wolfing as it'd mean that the Firehawke couldn't fire its main gun and move at the same time.
In my view, there's simply no rational reason not to do this. Sure, the other FPS games out there leave the driver in charge of the main gun, but those games don't have tanks with machine guns that are nearly completely ineffective unless controlled by the driver. FS, however, has two tanks and a walker with hard-to-aim weapons, and in every case except the Firehawke, the "problem gun" is controlled by the driver. Give the Firehawke tank commander the secondary gun and the gunner the main gun.
As for letting the guns traverse higher, we tried that in testing, and it just didn't look good at all as it clipped the main gun. As for letting it traverse down, we could do that, I suppose. It's not like the cap ship turrets don't already fire through the hulls of their ships.
"One of the bitches actually gave birth while she was attacking, and her puppies joined in on the carnage."
--the awesomeness that is Boatmurdered.