So it's easy for you to believe that a person who is compassionate, values harmony and cares about people's feelings can start a world war and kill and burn people, but it's hard for you to believe ENTJs can be kind and considerate to their guests and people of their country?
Yes to the former, no to the latter. Hitler wasn't INFJ because he was kind to his guests and countrymen, but rather because his values were not his own (Fi) and he had zero concern for efficiency (trademark Te). He was a visionary, whose vision was propelled by the values of his time (Ni + Fe). Further, he actually
was a compassionate man who valued harmony (which of course does not make him in and of itself a nice person). He was obsessively concerned with social order and organization, harmony amongst his ethnic group. He also had a profound ability to "connect" with people he met in private, according to statements by those who met him briefly (which are more trustable than statements by, say, Joseph Goebbels, for example - who did indeed say the same thing).
Yeah, that's what a lot of ENTJ presidents did for their countries. We like to improve on things.
Yes, but ENTJs are consummate pragmatists. They actually know what to improve and why. Hitler's economic plan contained exactly zero concern for whether it would work or not, and as a result failed spectacularly (much like his war management).
I won't comment on the last bit. You've basically labeled a nation as evil.
Not evil, typical. Man is by nature a tribal animal, whose instincts are to protect those of their own kin and society, in competition to those they deem foreign. Germany in the early 20th century was fiercely nationalist, which was the norm at the time. Among the general population it still is, but nationalism has completely lost support among all elite groups. Genocide has, indeed, occurred at popular request numerous times throughout history. All it takes is for a foreign ethnic group to encroach on what are considered "national boundaries."
As an aside, your argument still seems a bit too Fi-guided for you to be ENTJ.