If Blaise gets distressed enough, Seamus will definitely feel it. And you are very astute! Blaise and Seamus have sort of been acting as my foil for Harry and Draco. Their bond is definitely meant to give clues about what's going on with Harry's bond. *hugs*

And yes, the bond can definitely form unintentionally. It just requires strong enough emotions to get going. ^_^ Thanks so much for a great comment! I really enjoy reading them.