Yes. It should be St. Patrick's Day.
No, God decides. But it is St Peter at the gates of Heaven... perhaps you have confused the two.
Because Irish people have travelled all around the world and they and their descendants continue to celebrate St. Patrick's Day. As Ireland and its people are quite welcome wherever they go, locals in those countries have also joined in and helped to organise St. Patrick's Day celebrations.
Yes, Patrick studied for the priesthood in Europe, probably in Italy.
Yes they do. There are lots of special events that children like on St. Patrick's Day. They love parades. There are a lot of them on St. Patrick's Day. Many places have funfairs for children. Children also go to religious services on St. Patrick's Day, and sometimes they even dress up as St. Patrick.
Go to church, have a party, yeah..
Yes it is. It is in honour of St. Patrick who is credited with bringing Christianity to Ireland. It is Ireland's national holiday, and also a day of holy obligation, meaning that people go to their churches on that day. Around the world where there are Irish people, it is celebrated, though it is not a holiday in all of those countries.
St Patrick's college, Dungiven.
xx-St. Patrick's College-xx
St. Patrick's in New Jersey
St. Patrick Catholic High School in Miami.
Go to Google and do a search for St. Patrick. See below for a very commonly used image of him in Ireland.