Thanks for the crits and comments. As far as the cannons go, the model is still a WIP. That empty cylinder is the auto-feed loader mechanism. I'll put in the back as I go along. The upper cannon isn't finished either. Some of that is still place holders.
@Durant Carlyle - this isn't a Battletech mech at all. The missile pod holds 12 missiles (either 2 flights of 6 or launched singly) with armor piercing heads for anti-mech warfare. The lower cannon is a 50 MM cannon with a rate of fire of 10 rounds per second. The upper cannon is the equivalent of a 105MM howitzer but with shorter range. There will be a laser inboard of the missile pod, mounted high on the arm.
As far as the torso twist, I determined about 45 degrees to either side before coming in contact with the legs.
I've given some thought to the placement of amor. For one thing, I don't like beefing up the mech so it can safely run away. The heavier armor in back is to shield the power packs above the torso jump jets. I want the pilot only turning around to go home when the fight is over.
I agree that the joints are a tad unprotected, but they are small and hopefully, with its firepower, it won't give an opponent time to make a surgical strike against those locations