Nah. The book is a big metaphor used to explain the philosophy. Making the characters like that means they're harder to relate (I think to some degree, Rand thought she was Dagny) but easier to understand. Them being physically superior to me is a bridge between the abstract and the concrete of the philosophy, in that the characters embody their beliefs.
As for the presumption that her philosophy is true as a premise for the book, I guess it depends on how you see objectivism, and let's not kid ourselves, where on the political spectrum you consider yourself to be. To me, it's about inspiring to be competent, self-sufficient, reliable, virtuous, and that the pursuit of that is what gives life meaning. To others, from what I've heard, it ranges from being a selfish asshole to a worse 50's version of Twilight.
As for that world looking nothing like ours, I agree 3 times: 1 You and me probably live on different universes; 2 This world looks almost nothing like the gulch, and 3 our world is way worse than the one in the book :)