All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is his slave and messenger as well as that of his family and all his companions.
It is disliked for the person who works in a usury-taking bank or cooperates with it to lead the prayers. This is the preponderant opinion of Muslim scholars. The person, whose parents had married without the consent of their guardian, can lead in prayers. There is no relation between his leading the prayer and his parent's marriage. However, the majority of Muslim scholars dislike an illegitimate child to lead the prayers. But the one whose parents married without the consent of their guardian is not considered an illegitimate child at all. The ruling of marriage without the permission of the guardian is mentioned in Fataawa: 85026 and 82103.
Allaah knows best.