Weren't the phasers also arcing when the Vengeance was stationary and firing at the damaged Enterprise (with the moon as the backdrop), after both ships had come out of warp?
Neither ship was at warp at that stage, yet I thought there were arcing phasers (as well as the drones) in that scene also... or am I imagining things?
I might be missing that, too. At that point in the battle, my eyes were fixated on the explosions and the occasional photon torpedo (which, for some reason, seem to do just as much damage as phasers, at least for the Vengeance).
Edit: Yeah, just rewatched that scene. When Marcus maintains fire, the phasers travel a straight line. However, when Khan takes over the Vengeance and resumes fire, the phasers do indeed arc, like tracking shots.
Funny thing is, I also rewatched the warp chase scene, and a couple of the Vengeance phaser blasts arc but miss the Enterprise. Because they arc, they eventually fly out of the warp tunnel, which would give credence to the idea that phasers don't perform well at warp. However, yeah, then the arc the same way when Khan fires. Maybe he's trickshot with ship-board phasers?