Luckily it's part of Irish culture not to worry about things like that.

Sure some people might be offended, especially if you're an asshole about it. But generally Irish people are glad to share their culture, and delighted to see genuine interest from foreigners. Sad though our history is, we don't have the kind of issues that make some other groups more reluctant to share the symbols of their identity†.

† Notable exceptions apply, especially regarding English upper classes.