Creating a new religion is very hard. It is easier to work with a religion that already exists. Orthodox Judaism is not based on the Torah, but on the Talmud, so that is no good. Traditional Christianity probably wouldn't work well with other religions since it is so exclusive. I can't comment on Confucianism and Shintoism since I don't know enough about them. But I think Shintoism could be revived in Japan which would be good for the Japanese.