Its funny because we are of 99.9% agreement in most these points.
Even my world class tag is a slightly less simplified version of yours. e.g. mine has 2 main requirements. For my selection, "this player would not look out of place in a hypothetical world XI." For example, he can play alongside that calibre of player but also isn't a big drop down from the comp in his position, which I guess is where we differ. So if it is 2014, if you draw Robben or Bale as your RWF, probably happy with either. If it is the 2000s and you draw either Henry, Raul, Sheva, RVP as CF you are good either way. If you draw as a CM:Kroos or Xavi or Scholes or Iniesta or Gerrard or Modric. If selected and AMC and you draw: Zidane/Kaka/Ronaldinho. That said, my selection also mean that being the best in your position does not necessarily make you world class due to the fact that you could be in an era where your position is relatively weak. Imagine if Lauren was considered the best RB of his era, I don't think his quality matches up to some of the players he would be playing alongside where as guys like Dani Alvez and Lahm (different eras) were clearly of that calibre, if that makes sense?