They were part of the Empire, yes. But a separate Dominion until 1934 (when they reverted to colony status until Confederation in 1949). And the people most definitely considered themselves separate.
Marc Ouellet was considered papabili in the last conclave. The problem there, though, is that he has said numerous times he would never want the job. Of course, who knows how he would respond if he was actually chosen. I recall the Vegas odds of him being elected were not too bad either. Maybe...
It depends on where you are in Atlantic Canada. Newfoundland, I'm told, sounds rather Scottish-Irish, and Cape Breton does as well, which may have something to do with the long continued usage of Gaelic in certain towns. It certainly doesn't sound Scottish across the board, but there are...
The Atlantic Canadian accent is definitely very Scotch-Irish, especially Newfoundland/Cape Breton. You might have the Canadian population more concentrated in Atlantic Canada, which could be accomplished if the coal mines of Cape Breton and the iron ore in Newfoundland were discovered sooner...
An easier accomplishment would be stronger Cape Breton separatism. There is a certain amount of it now, and rather a lot of anti-provincial government sentiment in popular discourse. This all goes back to 1820, when the island (which had been a separate colony since the 1780s) was rather...