in general I look at feedback when dealing with international shipping. as I am pretty close to canada in general if your feedback is high enough, I'll give it a go but you cover the additional shipping charge, and it goes some insured method.
As for people responding or not responding, that happens regardless where you are at. Its common if someone loses interest in an item for whatever reason they just stop responding. Had that even happen with a guy in my town and his response when I asked him about it was that was his response.
It is what it is.