There's nothing to consider in the "ideas" you presented because they do not address one simple fact. In the end, Cobb's kids did not age, they were wearing the same clothes from his previous memory, and they were playing in precisely, frame for frame, the same position. Earlier in the movie, Cobb's children spoke in voices that were older than those of the children in the end of the movie. Those are events that happened in the movie that everyone can agree upon. There is no room for interpretation. There is no ambiguity. Those two things happened. That makes them facts about the movie. Rational, intelligent people form conclusions based on facts, not opinions or emotions. There's nothing to argue or disagree about. It's like arguing about whether or not the holocaust occurred. What I described above is what happened in the movie. It is not an argument. It is what happened. They are facts about the movie.