A popular misconception Oddquine. This battle was no more an Irish one than the war of the roses was a Scottish one. The opposing forces were King William III of Orange (protestant), who a few years previously had deposed King James II of England and VII of Scotland (catholic) from the throne of England, and the aforementioned James. James had fled to Ireland and was followed by the forces of William. They met and fought across the river Boyne. Irishmen fought on both sides of this battle, just as Scots had done in the English civil wars, but it was still very much a battle for the English throne.
Apart from that I agree with most of what you say.
I would, however, say to all our fans.....people will be among the crowds at games, especially those involving OF, and will act against those who use sectarian terminology.