Point b, as in the US being the self-appointed guardian of democracy?
No, b as in wanting to be seen. You said the world is fixated on the US because b. they want to be seen.
As for your culture being fed to the rest of the world, pretty much the entire western world prefers American TV to their own, which, for better or worse, colours their views.
The world prefers most everything about our culture, movies, tv, fashion, pop culture, food, go-cart tracks everywhere, whatever. My cousin is married to a Turkish immigrant who works as a consultant to aiding people from her home country gain US citizenship. She told me they all talk about the US and americans like it's the ultimate worst shit place in the world, but they all want to come here and when they get here they never try to leave. Some of it strikes as sour grapes mentality, while the rest is typical behavior of people minimalizing their own problems by comparing it to something worse. Not saying it's not a natural thing to do; just can't understand it, like when people say their life is good, not by their own personal standards of good, but by comparison to the worst of the worst in other people's lives. Americans do it too, but it doesn't strike as quite as weird when americans comfort themselves with the negativity of the lives of other americans; at least it's looking at the negativity of our own culture. Maybe because am more used to it, or maybe it's harder to understand why anyone else would be interested at all. Either way, it all seems self-soothing.
As for the celebrities, including the Canadians, it's a question of sheer volume. Until the petitions to deport Bieber made the news, quite a few people (in the rest of the world) didn't know he was a Canadian in the first place. America is synonymous with the US, for lots of people.
Already said no one would give a crap about beiber if he were famous in canada, and that's true.