Baptism for the dead is a true doctrine practiced by the early Saints. See 1 Cor. 15:29
Mission presidents, as well as persons called to any position in the Mormon Church are, in the last analysis, called by the Lord Jesus Christ, who inspires the appropriate authorities to issue the calls for missionary service.
Mormons believe that the Lost tribes will be literally restored and gathered again to their lands sometime around the Second Coming of Jesus Christ.
Mormons should help feed the missionaries of the Church as needed.
Mormons seek, when possible, to maintain good relations with family members, but the Lord Jesus Christ comes first.