there are probably 1000s of restaurants in Ireland, as in any modern country of 4 million people
Ireland has many McDonald's restaurants all around the country.
Yes, Mastercard is widely accepted in Ireland at most major retailers, restaurants, and businesses.
There are lots of restaurants in Cork, too many to mention. Try the link below to find some.
Yes, absolutely. There are many Italian restaurants throughout Ireland and spaghetti is also readily available from local supermarkets.
There are many in Dublin. See the link below.
Crisps are called crisps in Ireland. However, what Ireland refers to as crisps are called potato chips in the USA. What Ireland calls chips are called French fries in the USA. You will only hear the term fries in fast food restaurants in Ireland.
They may not be hugely popular, but you will find them in restaurants and supermarkets without much difficulty.
They can be called Pizzerias too, or some other names like pizza restaurants.
Only in the minds of Americans and owners of the 'Waxy O'Conner's' chain of restaurants.
SuperMac's is good. It is pretty much the Irish version of McDonald's.
Euros aren't legal currency in Northern Ireland but some of the alrgers pubs especially those around the border may accept them.