I split my time between houses in the USA and Europe. What you want to do is dead simple and you can easily ignore some of the nannies on this thread.
Buy in the USA wherever you want. On-line Apple if you want a different keyboard. Deliver to where you want. The hotel your relation is staying at works, safer to send to someone you know.
Now 2 choices: The issue about it being turned on can be avoided by simply putting it in checked baggage. No checked baggage, buy a cheap sleeve, unpack (as in leave all packing behind) go through the security check with it in sleep mode. Turn off once on plane. With either approach, at customs, simply walk through. The odds of being stopped and the bags checked is <tiny.
The charger works fine. The warranty is just fine.
I have no idea what prices are like in Ireland. Here in Switzerland, the prices have come down dramatically over the years and are now close to parity with the USA. For about a $20 difference, I can buy but not with a USA keyboard. So I resort to the above.