1) Santa Claus CAN be disproven. Nobody can disprove the legitimacy of Judaism or Christianity.
2) Why did you tag your argument as judaism? You questioned Judaism's legitimacy and didn't even answer the main question: Islam vs. Christianity.
a) Roman Catholics still don't eat meat on Fridays, with the exception of fish.
b) You say homosexuality should be acceptable because it has no negative impact on society. But it does negatively impact society by going against nature and by going against almost every organized religion on the planet: not just Christianity and Judaism, but also Hinduism, Mormonism, Islam, and countless others. By advocating acceptance for homosexuality, you are opposing the beliefs of a majority of the world's population.
c) Take that, heathen! lol