This Shylock thing broughts to my mind Caliban in "The Tempest". There are those who see in him an portrayal of the enslaved populations of the New World and those who think that he´s just a monster and nothing more. I would go with the latter interpretation. Much of the depth that people think that exists in Shakespeare´s plays are because of the ambiguity that gives room to different ways to interpret them. But how much of this is intentional? I think that very little. But that doesn´t mean that we have to stick with the original portrayal of Caliban or Shylock; you can make a play based on "The Tempest" where Caliban is not a mere monster, and you could do a play or movie that concentrates on Shylock´s character and sheds the antisemitism and makes him a true, tragic hero. After all, Shakespeare has been dead for almost 400 years. He ain´t coming to complain if you meddle with his works - even if a huge mob of literary scholars would... And frankly, many of the movie adaptations suffer because they stick too close to the plays and carry on with them subplots that are there for just comical effect, have little or no artistic value and should just be dropped.