Everyone has some form of tradition that is passed though generations of families, most of which we never bothering exploring.
Favorite Irish drinks - "When in Rome ..." applies to any place in the world, really. Especially when it comes to food and drink. True, you can survive an Irish holiday on Big Macs and Coke (or Whoppers and Pepsi, for the sake of variety). But will you really have experienced the local cuisine? No - and going into a pub and drinking just Bud Light should be positively discouraged. If you want to down a few, why not try the local brew?
Most visits to Ireland are trouble-free but you should be aware of the global risk of indiscriminate international terrorist attacks, which could be against civilian targets, including places frequented by foreigners.