I'll answer some of your other points here too.
Yes soccer is the fastest growing sport in America, probably Canada too (I haven't looked this up but am willing to continue under the assumption that it's true).
What I can say for certain, is that the reason for its growth is not because North America is finally coming around to the amazing game that the rest of the world plays as the greatest sport. It's because it's so oooo much cheaper for parents to put their kids in soccer than hockey or football, and it not being a physical contact sport, so parents don't have as much anxiety of wondering if their kid will come home with a broken femur, concussion or any other major injuries.
Contact sports are getting to be prohibitively expensive for alot of people. Soccer is a very easy, simple, safer and cheap alternative that's still really enjoyable for kids to play.