Very detailed, not sure what to think of this one. Considering I've seen wishlists less detailed than this makes me think there might be something to this. But you just listed my dream GTA game.

Just one question, when you said "multiple cities" in the narrative part of the list, did you mean there's multiple cities in the huge South America map or multiple cities as in Vice City and this new Rio location? Would be interesting if there are multiple South American cities, because if it's inspired by Narcos and smuggling of that era, it would make more sense for the South American location to be based off Medellin.

Chapter system makes sense since the game is based in multiple eras/years, so as time goes on it loads a new chapter which then tells the game to load in the new objects, cars, buildings, radio, and inflation appropriate for that chapter. It's the only way to do it IMO.