There's actually no reason why this mech can't aim *straight up*. When it's crouched and aiming all the way up, the cockpit is unobscured enough that if you simply adjusted the player's vision, they can look directly up without any view obstruction. The missile racks, literally, are aligned parallel to the ground. The arms, given their design, just need to rotate some and again, they're aiming straight up. Furthermore, 360 torso twist would make this thing more than an aero rapetrain, so much so that we'd need to invent a new word.
The only way this could be better is if Darth Vader stood on the nose while you did this and melted faces with a bitchin' guitar solo.
Don't believe me? Check this shit out.
http://i.imgur.com/D5vUn.jpgSee the concrete pillar behind the cockpit in the first shot? That's looking straight up. The actual roof doesn't begin until the angled part ends. It's literally one of the best cockpit views around.