I do not know about Sins as such, (there were some which required the offices of a Bishop to pardon, at one time as he is the Chief Executive officer of a diocese- certain sacraments- Ordination and Confirmation, require (Episcopal) consecration, as it were. in the canon laws regarding Marriage, there were certain types of mixed-religion weddings that did require special permission and dispensation as it was called, from Rome- for example a marriage in a Catholic Church between a Jewish Man and a Catholic Bride would be such a case, owing to (Disparity of Cult) which is a more serious impediment than say a Catholic and a Lutheran- which my parents were and there the Lutheran had to make some adjustments, attend classes (orientation, not conversion) and so on. I believe this Papal angle would have had to have been invoked int he case of the Marriage between the late Anna Moffo- the Opera star and RCA Executive David Sarnoff, Jr. as he was Jewish. The whole aim and objective of such restrictions was to keep the faith pure, and discourage interfaith marrriages. No such ban existed on race-mixing as far as I know, however.
By confession and genuinely repenting for your sins.
In the Roman Catholic sacrament of confession, you confess your sins to a priest.
Confession.
When you admit your sins to a priest it is called a confession. Some say it is better to confess your sins to a higher power so that it is only between you and them.
Just like any other Catholic, the pope goes to confession to confess his daily faults and sins. Usually he has a specific confessor of his own choice whom he visits or is visited by according to a weekly schedule, however, should the pope fall into grave sin or have a terrible scruple, he might approach his confessor for an immediate confession. The pope may himself also administer the sacrament of Confession to whomever in any diocese of the world as he is the universal bishop of the Church.
it means confessing your sins
According to paragraph 1457 of the Catechism of the Catholic Church, Catholics who are aware of serious sin must go to Confession at least once a year. Confession is also suggested for anyone in need of confessing smaller (venial) sins. Pope John Paul II is said to have gone to Confession once a week, despite his holiness, because as a general rule, the holier a person gets, the more aware they become of their sins.
Confession
The pope has a personal confessor, usually a priest.
Yes it is necessary. A priest can't "hear" his own confession. Even the Pope has to confess his sins to another priest.
No, We confess our sins to God directly.
God forgives their sins in the same way as He forgives the sins of Muslims or Buddhists or Hindus or... He forgives them if they repent. As Jews are not Catholics (or Orthodox), they cannot go to confession.