Understanding Catholic Beliefs: Transubstantiation and Mary's Virginity

Questions Covered: 

• 05:53 – Catholic, married Methodist. He has a divorce; they have a civil marriage. I’m told I need to get an annulment. Why is this?
• 12:20 – I’m not Catholic; why does the Catholic church believe/profess the doctrine of Transubstantiation?
• 20:11 – I come across a lot of Protestants who have trouble with perpetual virginity of Mary. Who is James (“brother of Jesus”) in Gal 1:19; is he one of the 12 apostles?
• 29:40 – Is the celebration of the Eucharist/the Real Presence greater than the miracle of the Last Supper?
• 33:58 – It doesn’t make sense to me that John the Baptist is described as “the spirit of Elijah’, whereas the prophecy makes it seem as if Elijah was to come back?
• 41:19 – I’m Catholic, but I’m interested in Orthodoxy. Some of their claims seem to have weight. How can the Church change its position on topics?
• 47:37 – Where do we get the idea/doctrine of indulgences?