The holy language for Jews is Hebrew.
Judaism
Hebrew!
Hebrew. Although, it is important to note that the term "official language" refers to a national government, which Judaism does not have. While Israel is a Jewish country, it is not a country ruled by Judaism. (This is as opposed to Vatican City which is a nation ruled by Catholicism.) Judaism does have a sacred language and a religious language (both of which are Hebrew), but the term "official language" is not apropos.
Judaism is not a sacred text, it is a religion and that religion happens to have a sacred text. To learn more about Judaism's Sacred Text, read the Related Question.
No. The cow is the sacred animal in Hinduism, not Judaism.
Mecca
The Torah
Judaism accepts parts of the Christian Bible as sacred, but treats the entire Jewish Bible as sacred.
No. The sacred writing of Judaism is the Bible, also called the Tanakh. The Vedas are one of several Hindu Holy Books.
What is sacred to both are the Torah, Psalms, and the Old City of Jerusalem.
The Old Testament is sacred to Judaism
Judaism has no sacred people. All people are equal in God's eyes. There are different classes of people in Judaism; Cohen - priests, Levites and regular Israelites.