If you were born in the US, it will always be shown on your passport and driving licence. This will limit the choices you have in making future investments...as stockbrokers won't take you on as a client due to reporting obligations.
Not sure if the IRS has a claim on assets in Ireland. I know there is a $60,000 threshold on assets owned in the US going to a foreign spouse. This too is largely ignored.
The US is one of two countries in the world that taxes you on citizenship and not residency. It causes people a lot of hassle each year. There are a lot of people, especially PAYE workers who simply ignore their obligations. The IRS have enough on their plate collecting taxes from people living in the US as it is