I'd say he's comfortably top 5 in the world.....Of players around his age
Ibrahimovic
Alonso
Yaya
Lahm
Alves or Robben
Maybe, but he's the only one playing in the Premier League. Playing for Bayern or PSG is far less intensive as the domestic season is a doddle.
Yaya would be great at PSG for a couple of years or be the best player in Serie A next season. He's not got the legs for the Premier League anymore.