The “without god there is no morality” argument is actually saying that without God, humans decide what is morally right and wrong, creating a false morality.
None of these points really make sense.
Not likely to survive isn’t impossible.
Prayers don’t have to be answered, sometimes they are, but in ways you can’t see.
The whole Old Testament was supposed to be filled with people pointing towards Jesus, it would be much easier for these books to be preserved if the prophet/leader had gained some recognition, that’s why there were so many miracle workers in the Old Testament. We don’t need that now, as Christianity has spread all over the world. It has been, and will be preserved forevermore.
Jesus promised to rid the world of sin after his second coming, not his first.