Why do Catholics pray to Mary and the saints?

Questions Covered:

 

15:51 - Do souls in heaven have the authority or ability to intercede for those who are living? 

21:05 - Protestants say that the saints will not pray for us because they are too involved in the adoration of God to worry about any of us on earth. How can I respond to that? 

24:08 - My father passed away on Friday. He wanted his ashes to be spread in the gulf. Is that acceptable in the Church? Why or why not? 

33:23 - How does Mary receive my prayer requests if she is not omnipresent? 

42:00 - When the saints intercede for us, do they just intercede to Jesus or to the entire Trinity? 

46:45 - Whenever I talk to a Protestant, their first objection to Catholicism is praying to Mary, saying there is no biblical evidence for it. I reference the wedding at Cana. Am I going about this in the right way? 

51:41 - Protestants ask me why Paul or Peter didn’t pray for the intercession of the Old Testament saints in Scripture. How can I respond?