Woah, loads of questions. I can't really answer all of them coz I'm not a Muscle car fan although I do have a number of American cars. I think the web can give you the answers you seek but in relation to Hot Wheels, a large of number of cars released are Amercian coz USA is the biggest market for Hot Wheels. It makes sense for Hot Wheels to release more of these cars. I guess in-depth knowledge of those American cars would increase appreciation of your Hot Wheels collection but I think it is not essential to enjoy racing your cars about and liking cool flame decals. Like me.