Can the president use the military to kill his rivals or anyone else they choose? Sure!
Is it OK for the president to commit crimes? Of course, being the president of the United States apparently requires breaking the law!
To recap, we vote for president and the man who gets less votes still wins because of the electoral college. The president appoints some judges and the citizens have no say in those choices either. Then the supreme court decides our president is actually more of a king. What's next?