I can respond for my understanding of Biblical Christianity.
1. How many Holy Books are acceptable so far? Which one is more accurate?
I believe that 66 "books" of the Bible are inspired by God and useful for all aspects of Christian life. I believe that other Jewish and non-Jewish writings are helpful to life and contain truth, but are not "inspired" in the same way.
2. Who represents your Religion today? The Body + Head?
In my view, the "head" is Christ; the "body" is the universal Church worldwide. Only the apostles' teaching as recording in the New Testament speak for us. As a worldwide community we read the Bible from our different perspectives. Tradition and Popes and Authors and Priests and Pastors and Evangelists are part of that reading, but contain no special authority except spiritual maturity.
3. Is your Religion changeable? Or was IT Changed? By who + When?
Christianity hasa central biblical core that is recommunicated using different metaphors and restating its myths to each new culture and generation.
4. How many divisions are there within your religion? Why?
Tens of thousands. Christians splinter like fine wood.
Because we have no single theocratic head, Christians have reacted to attempts of some groups to hold that authority by splitting instead of experiencing diversity as a local community.
5. Does your religion hold the Sate + Religious Authority separable or inseparable?
Seperable, although faith is political, and politicians can be faithful (or unfaithful).
6. Could the 2 heads — State + Religious Authority— be One?
Leaders can be Christians, but that does not make them a religious authority. "Christendom" is not helpful to biblical Christianity.
8. Should the 2 heads go complementary or in different/opposite directions?
I think power will always corrupt spiritual leadership, and power brokers will use religion for their gains. Look at the Abbasid or the Umayyad dynasties.
9 Is the Religious Authority allowed to interfere in the State affairs?
The questions are becoming irrelevant to my view, since the two figures are disconnected. But Christian "authority" is biblical, so the faith community should always be critiquing the State.
10 Is the State allowed to interfere in the affairs of Religious Authority?
I hope not.
11 Who accused the Infallible Mary — Jesus’s Mother— with the unspeakable?
I don't know what that means.
12. Who was responsible for Jesus’s crucifixion?
The Romans. Some Jewish power brokers tried to show influence in that direction--or at least suppressing Jesus' movement. But he was killed by Roman oppressors as many Jews before and after him were.