Irish-Americans are less ambivalent about their roots than many other people of European descent - being excited about being part-German in Missouri is tantamount to being excited about watching paint dry, for example - and the fact that a man of Irish descent was President of the United States within two centuries of the "famine" and after centuries of oppression by the English boosts the credibility of America as a "land of opportunity", even if only in retrospect.
They definitely can't, given that tax decisions require unanimity. Like, if they didn't get this sorted when they had Ireland over a barrel in 2011, it's probably not going to happen. Full disclosure: I am an Irish citizen.
Still it would not be very hard for individual countries to find indirect ways to tax them individually. Like putting 50% VAT on extensive phones to target Apple, or on application stores revenue, etc.
Again no. VAT is also managed at EU level. The digital services tax could be done. The best thing would be to implement the full beps agreement but the US don't want that.