I believe I may be a [very distant] cousin of yours.
I believe the Pierre Bourbeau you mention is the one who married Anne Besnard?
Although difficult to substantiate, I believe he was the son of Simon Jean Bourbeau & Francoise [le]Tar[d/tre], my 8th gr-grandparents. I've been hoping to come across some other possible descendants...and I'm particularly hopeful that some will have the ability to compare some DNA.
Take care,
-Bill Bourbeau