A question about the weapon fittings, the spec listed two fixed mount on wing and one gimbal mount on nose, but I see from the released arts that the two M3As are mounted on a ball shape unmanned turret, which will be the case?

The 2 M3A's mounted in the concept art are installed in place of the Tractor Beam (guns are sexier anyways). When the Reliant lands in your hangar, you'll have 2 Size 1 guns on the wings, and the S3 hardpoint on the wing-tip where the Turret is now.