As for majorities - had the entire island of Ireland been given the vote on independence at the time, it would have voted overwhelmingly for Indendence

Opinion masquerading as fact.

Had Ulster as a whole been given the vote, the result would have been the same.

It wasn't and you have no way of knowing with any degree of certainty how people would have voted. Again opinion masquerading as fact. And just because an author states an opinion or the opinion of someone else in a history book does not make that opinion a fact.

As it was, the decision of permanent partition was taken unilaterally and secretly on behalf of the Ulster Unionists, who claimed to represent two thirds of the six counties, but in fact were a minority of the population as a whole, a minority of the Protestant population and divided among themselves - a minority of a minority of a minority.

Ah you mean much in the same manner as:

As it was, the decision to instigate and mount an armed rising was taken unilaterally and secretly on behalf of the Irish Volunteers by seven men, who claimed to represent the entire movement throughout Ireland, yet who had to keep their plans secret from the executive committee and membership of that organisation and were in fact representing a minority of the Irish Volunteer Movement, a tiny minority of the population and divided among themselves - a minority of a minority of a minority.

However in the case of the Unionists they had lodged their objection in 1912 when the Bill was first introduced, those objections were given in Parliament by the MPs for Ulster elected by the people of Ulster. I think Keith supplied the demographics but a massive percentage of the Protestant population of the North signed the Covenant and Declaration in 1912 stating clearly that they would resist Home Rule by all means necessary. No such clarion signal was given in support of Independence in the South at that time - support for Home Rule yes, but independence No. Agreements relating to six year temporary exclusion came to nothing in part because of the Easter Rising and the Unionists in the North saw exactly the style of Government they could expect from Dublin after the 1918 General Election. The Government of Ireland Act 1920 called for two autonomous self-governing areas on a temporary basis, the Unionists accepted this and established their own Parliament, the Sinn Fein Government in Dublin rejected it and fought the Irish War of Independence, tell me why didn't the whole of Ulster fight for Irish Independence if what you said above was true? The war which resulted in a stalemate was brought to and end with the negotiation, ratification and signing of the Anglo-Irish Treaty which gave six counties of Ulster the option to secede from the newly created Irish Free State and that is exactly what their Parliament did one day after the creation of the Irish Free State was announced (6th December, 1921, Ulster seceded on the 7th December 1921). Hardly unilaterally they'd been discussing it for damn near ten years.

Their power came from the barrel of a gun and they were prepared to plunge the whole of the island of Ireland into civil War (when it was still a part of Britain) in order to mantain that power."

Nope their power came from the display of solidarity displayed in 1912. In comparison the Pearse faction of the Nationalists their power really did come from the barrel of a gun and they actually did use them, in Dublin in the Easter of 1916, during the War of Independence and then again after they had refused point blank to follow the democratic will of the elected representatives of the people of the newly created Irish Free State when they actually did plunge the newly independent state into a Civil War in an attempt to overturn the treaty and impose their will on the people. Please don't say that "the people" supported them - they didn't only 3.33% of the population turned up for their idiotic and totally unnecessary civil war.

Tell me Jim is the United States of America any less independent by being a Federation of independent states each of whom have their own state executives, legislatures and judiciaries?

Is Australia any less independent by being a Commonwealth of independently governed states with Queen Elizabeth as Head of State?
During WWI when expansion of their Commonwealth Defence Act 1911 to include service overseas was being discussed in Australia the plebiscite was run on a state by state basis, three voted for expansion and three voted against. Being a plebiscite all votes were lumped together and counted and those opposed to the expansion of the Act won.

Is Canada any less independent being Confederation of Provinces each with their own self ruling Parliaments?

The Unionists in the six counties wanted nothing to do with a united independent Ireland in which they, according to their perception, would always be a minority and in which they would always shoulder the main burden of taxation, their trade and industries relied heavily on being part of the United Kingdom, being part of a united independent Ireland was simply not in their best interests and they said so very plainly, when no-one in either Dublin or London paid them any attention they registered their objections in an even plainer manner, signed their Covenant and formed the Ulster Volunteer Force. Now then that had nothing to do the interference or imposition by any foreign power - That was simply how a large minority group of Irishmen in the North viewed independence. Or are they still to you "Blow-In Newcomers" from 500 years ago with no right to speak of at all? No right of self-determination.

In 1914 both Redmond and Carson had agreed to a temporary exclusion for Ulster and had the nationalists held off and had the Easter Rising never happened I believe that the two sides would have come closer together. But that is not what happened and the events of Easter 1916 polarised and hardened views of both nationalists and unionists.