Thank you for your question. I am sorry that you had to wait. I seem to be the only active expert in European Law and my day job as a lawyer took my time.
The answers to your questions are:
1. Ireland will not care. Such a criminal record is no bar to your possibility to obtain a work visa.
2. They will ask for an US criminal record, so you should declare everything. In fact, it is more risky not to declare the court order violation, than declaring it. Not declaring is in itself an offence in Ireland, and besides the penalty (most likely a fine), it carries the automatic option for the government to cancel your work visa.
Therefore, do declare, ask in advance for a criminal record from the US, to have it ready, and it will not count against you.
I hope my answer was useful and look forward to your rating, which is essential to my activity.
Dr I L Vlad