"it's not *my* culture to treat as trashily I want to, simply because I have some 'green' chromosomes."

I get your point, but it is based on a premiss that the leprechaun beards etc represent trashy treatment of Irish culture.

In fact they are a perfectly valid part of Irish culture, that those who do enjoy would probably love you to participate in.

Of course there is a time and place for everything, and Irish culture is made up of a myriad of other ingredients.

However, if your rationale is right - and as an outsider you are not qualified to make statements of Irishness that include wearing silly hats, beards and hamming up well known Irish songs - then by the same token, neither are you qualified to make value judgements regarding the authenticity of aspects of Irish culture that you see represented in your local O'Neills.

Which leaves you in a kind of self imposed stalemate.