The first part is pure fantasy. The first written examples of Hebrew, for example, are short texts from the mid-8th century BCE.

Everything you write about Palestinians beyond the anthem is just wrong and I bet you know it. Even "liberal Zionists" Kimmerling and Migdah in their "The Palestinian People" date Palestinian identity (and national struggle) back to 1834.

Palestinian National Congresses were already meeting in the 1910s. Those who established PLO in 1964 included members of Palestinian parties of the 1920-1940s and participants of the 1936-1939 uprising against the British rule.

Palestinian flag was the Palestinian flag already in the 1930s and then it had the Muslim Crescent Moon and the Christian Cross in it, which were later removed to make it religiously neutral.