Well, to determine if your airplane is gonna pitch upwards or downwards, the pressure moment may help you, however, it depends where you set the center of rotation, as SimScale integrates all the pressure forces around that particular point (check out this link: Forces and Moments | Result Control | SimScale) . As you know, you should set that point in the longitudinal position of the CG.
However, I am not liking the fact that the results do not appear to be converged. I am not sure if the simulation blew after the 800th iteration, but such variation of the values should not occur. Can you please post the velocity, pressure and turbulence convergence plots?