Students at a Brooklyn public high school shaken by shocking reports of antisemitism say most of the problems come from a specific group of troublemakers who “take it too far.” Bombshell allegations at Origins High School in Sheepshead Bay that surfaced over the weekend include claims from staffers that one student donned a Hitler mustache while a crew marched through the halls with Palestinian flags chanting “Death to Israel.” “It’s only a handful of students,” a high school junior told The Post Monday, the first day back in class since the accusations emerged. “It’s disheartening and I understand they are...