The Irish question! First declare my interest. My mother regarded herself as Irish. She was born in 1911 in England, as were her parents. At that time, Ireland was part of the UK. My grandfather was a supporter and member of Sinn Fein, and was all for Irish Independence. He resigned from Sinn Fein in around 1921 due to his 'disgust' (my mother's words) with the Irish Civil War of 1922 on. I am a Catholic of sorts, and was educated by the Irish Christian Brothers in England. To have that background in the UK in the 1930s was to be 'from the wrong side of the tracks', which was still evident after WWII to an extent.
As part of the deal the Irish were part of a Common Passport Area, and could live and work in the UK without restriction without need of a passport, and the UK citizens had reciprocal rights. Many people from Ireland did in fact come to work in the UK post independence. Some Civil Servants such as Officers of Customs & Excise could choose to work for the UK or the Irish equivalents.
Many young girls came to the UK to train as teachers and nurses, particularly near ferry ports such as Liverpool. Catholic priests were common too, some even regarding themselves as missionaries. One British Bishop took exception to that in my hearing!
When the question of the EEC, or Common Market, arose (President de Gaulle vetoed the first UK approach), the Irish did not want to lose their CPA rights, and for that reason alone would have joined with us I expect.
The Irish did not do so badly out of it at first, but suffered somewhat post 2008. I do not know for sure, but I expect the CAP suited the Irish with their large number of small farms caused by them not having primogeniture as the basis of inheritance.
So I arrive in County Clare the weekend after the referendum, and am very charmingly but pointedly asked what on earth we Brits think we are playing at! I was a bit surprised as I had not considered the Irish position when voting. Clearly they have a concern re the CPA for one. They also dislike the idea of a border with Northern Ireland, which everyone pretends does not exist - but which I have helped to police in the 90s. There are still duty considerations between the two States, as with the rest of the EU. Just try and take a van load of liquor or tobacco from the EU through Dover to find out what I mean!
My first reaction was to think that when the Irish demanded independence, and got it, they had to take the rough with the smooth. If I should need a passport to visit Ireland, so be it. But the demand in the papers that weekend seemed to be along the lines that the UK was being selfish and disregarding the interests of the Irish. I did not see the strength of that at all. I still don't. The Irish might possibly have to choose between Schengen and the CPA, but not necessarily to my mind. As to the Border with Northern Ireland, I don't see the issue, except for the pan irish people. Should Northern Ireland choose to secede from the Union, what would be the problem?