You do understand that Days of Future Past reconned the X1 - X3 so none of the events in X1-X3 happened including the scene in X2 where Xavier nearly kills every mutant. My point being is that NO ONE KNOWS THE FUCKING EXTENT OF HIS POWERS especially the government UNTIL the event in Westchester occurs.
Your only gripe seems to be you think no one died except 6 or 7 people. If that were the prerequisite then Wolverine (Weapon X) would be considered a "WMD X" along with all of the X-Men and any other mutant with destructive powers. Charles proved that he could kills MASSES of people. Why they fuck do you think Xavier's so apologetic to nearly the point of tears to the people in Vegas? You think it's just because he gave them a slight headache?
Oh, you think it's because he gave them a headache. >hey this guy is giving people headaches! label him a WMD! anyone have any tylenol?