> No culture deserves respect.
I don't know if I agree with that, but I will say that people in general deserve respect. If I were playing with an Irish player, I definitely wouldn't want to offend them by treating their language like set-dressing, and I wouldn't particularly want someone using my culture for that, either.
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.
Irish mythology gets bowlderised plenty, so we've a pretty thick skin about it these days. If you _do_ treat it well, any Irish players who have even the remotest interest in this kind of thing (which anyone playing TTRPG probably would be), would really appreciate it.
So, thanks for trying to be cool about this stuff!
Oh, I'm... absolutely going to steal things from Irish mythology in my game, and adapt it to suit my setting & plot so far. In fact, my players are about to leave "fantasy iceland" to go to "fantasy ireland", probably next session, so I need to read up on a few things to see what I can steal & borrow!