JFK are the initials of US President John Fitzgerald Kennedy
Riverdance is traditional Irish dancing, with rapid leg movements while body and arms don't move.
The Blarney Stone is a block of bluestone built into the battlements of Blarney Castle, about 8 km from Cork, Ireland. According to legend, kissing the stone endows the kisser with the gift of gab (great eloquence).
Hockey Mom is a term widely used in Canada and USA, where mothers (and fathers) often take their children to ice hockey rinks. Sarah Palin described herself as a hockey mom.
Canon Stephen Neill is the Church of Ireland rector.
Auld Sod is an affectionate name for Ireland, meaning "the old country".
Here is the old video in a previous post.