1.Is it really true that sexual morality of Christianity was never from Jesus christ?
Other than the ban on divorce, (which is from the Sermon on the Mount), yes its true. Most of it is just whatever sexual morality pre-existed Jesus.
2. If so,was Jesus christ really open about sexuality or just indifferent?
Jesus was by no means open about sexuality, nor was he indifferent. According to Jesus, looking at a woman with desire was as sinful as adultery. Whatever the Orthodox Jewish sexual morality was at the time was most likely Jesus' point of view. He was like a Jewish fundie, and would probably be horrified if he knew he'd started a new religion.