Joey, this is just my opinion, but I don't think the intent of some of the posts was to discourage your kilt-wearing in general, just in the instance of the UN function and/or the Viennese Opera. I've never been there myself, but from all I've read (here and elsewhere), I get the sense that Vienna is a really (proudly) conservative city, and some expressions of individuality - particularly in men's clothing - are frowned upon at particular social events.

I'm also a proud Scots-Irish-German-plus-a-couple-of-other-ethnicities American mutt. Unless I were officially representing a Scottish-American organization of some sort (a St. Andrews Society or similar), or playing my pipes for some reason, I wouldn't wear my kilt to a formal UN function - but then, I've never been invited to a white-tie affair either, so I haven't had to worry about it.

For an analogy, I'm quite proud of being an active Scout leader and Eagle Scout, but I wouldn't wear my Scout uniform to a formal event unless I were representing my unit or the local council and was requested/instructed and permitted to do so. Neither would I wear my Eagle medal on a suit or tuxedo, unless requested/instructed/permitted (usually that's reserved for Eagle award ceremonies).

By-the-by, it's only been in the last couple of generations that Irish-Americans really started celebrating their heritage, except in the larger cities. It wasn't that long ago that many Irish-Americans couldn't get a decent job, have access to decent healthcare and/or education, etc. While I was growing up (I was born in the late 1960's), my grandfather still downplayed the fact that his mother (my great-grandmother) was born in Ireland, even though she died in 1953. I didn't know it until after he died when I was a teen.

I hope you'll reconsider and at least check in on the forum from time to time.