Hi Ken - on point i): I've read it and passed the info on to everyone some time ago. The info it contains appears in Burke's peerage as the family tree we all now possess (re. the Portarlington branch). It is handwritten, and it was from that document that I learned of two William Halpin's, formerly of the RN, residents of Portarlington/Dublin, both preceding Nicholas Halpin. No dates were given. So: we have William Halpin (RN), followed by W. Halpin (RN), followed in turn by Old Nick and William Henry Halpin and the Rev. N J Halpin, and so forth - you know the rest. Brothers and uncles must have been John and Pagett, etc. Personally, I'm inclined to think that the Wicklow branch of the Halpin family emerges from one of these early Portarlington Halpins - from one William or another. But I'm only guessing.
I know nothing about point ii).
I've read the documents listed in point iii), but I didn't think there was much of interest to us. Mostly stuff about who owned what property where in Wicklow town, and who leased what to who, and for how much. I think that's where the Bradleys are also mentioned.
As for General William G (or J - depending on your source) Halpin, of county Meath. Well, I have reams of stuff on the chap. We were told that he and Charles G Halpine were cousins, and that together after the civil war in the US, they hatched a cunning plan to win freedom for Ireland in the Fenianian rising in Dublin in 1867. William would defend himself manfully in court, while Charles would lead a powerful press campaign arguing for the rights of Irishmen to bear arms against their oppressors (the British) and govern themselves. It was hoped that the British public would sympathise with the Irish and put pressure on their government to cease its 'enslavement' of the Irish people. The British public had done something similar before, when - with the guidance of Wilberforce - it petitioned its government for the end of the slave trade. Charles G Halpine thought he could convince the British people to do something similar for the Irish, using the trial of Gen. W G Halpin and his subsequent imprisonment as pretexts for said campaign. Well, all was going according to plan until Charles took an overdose of a drug he used to help him cope with the effects of alcohol withdrawl. He died in a New York hotel and the General was left to fend for himself in Ireland.
I swear to God I wish this were true, but I think it's baloney myself. A great story, but with no basis in fact.
Well - with none that I know of.
Yet.