1. In 1890, there were 43,000 Jews, 57,000 Christians, and 432,000 Muslims in Palestine. In 1948, the number of Jews was 630,000; of Muslims, 1,181,000. That does not come close to suggesting as many Arabs came as Jews. A population doubling in fifty years is not unusual; a population increasing 10x in as many years is.

By your terms, Israeli identity did not exist either until the UN granted Zionists a state.

Wikipedia is good on Palestinian identity; you can check the footnotes for anything you doubt: https://en.wikipedia.org/wiki/Palestinian_identity

By the terms you're using Palestinian identity began early in the 19th century, while Israeli identity did not begin until Herzl at the earliest.

2. Developing something you stole does not give you a right to it. Must I point out that you're employing Nazi logic there?