The Lord's Supper is a way in which we commune with God following baptism. Doctrine holds that the wine and bread are merely wine and bread, there is no transubstantiation. The elements are not to be worshipped. Prayer is to be used only for the living. It is not necessary to pray for the souls of the dead because they are already in heaven or hell.
Purgatory is nonexistent in the Presbyterian theology.
The pastor of the church is allowed to marry. The Presbyterian church ordains women as pastors and gives them many leadership opportunities in the church.