This is a very interesting question as i have wrote some essays on hamlet including themes such as madness, duty & freedom hope this helps?
: A)Madness being one of the most significant themes in the play, as this eponymous character Hamlet is not the only character in the play that is mad. Although it is mostly ophelia and hamlet that mainly illustrate the idea of madness in the play, they both portray this madness through different ways although their madness is driven by the same causes.. Hamlets madness more or less stems from a mental illness (depression) & (schizophrenia- seeing his fathers ghost) At the beginning of the play, Hamlet is visited by the ghost of his father. Seeing a ghost could indicate that he is already mad. His father’s ghost tells him that he was murdered by Claudius, which drives Hamlet to want to seek revenge. This causes him to display erratic behavior, indicating that he has become mad with his desire to avenge his father’s death. He also becomes quite melancholic over the death and murder of his father and begins to question life as a result. While Hamlet feels the need to avenge his father’s death, he also worries that the ghost may actually “be a devil who will betray his soul,” This makes Hamlet confused as to what he should actually do in response to seeing the ghost and drives him further into madness.
B)Claudius has more freedom compared to any of the other characters because of his power. Within the play, Claudius is able to reach his ultimate goals before the play even begins by marrying the queen and obtaining the position as king. He continues to prove his freedom as the controller of the traps in the play and has the power to control the characters’ freedom with the use of these traps. Even as Hamlet attempts to trap him, Claudius is able to escape both times, showing the control he has over his freedom. When focusing on the power structure of the characters, critics fail to recognise that although the characters in Hamlet are controlled, Claudius is the only character that has power over his freedom and that of other characters.
c) Principally, Shakespeare interweaves the theme of duty into the play through the character of hamlet who’s duty in the play is to avenge his fathers most ‘foul and unnatural murder’ in act 1 scene 1 hamlets role as an avenger is defined by his fathers wishes that ‘with wings as swift as meditation or the though of love may sweep to my revenge.’ Setting up hamlets final obligation as a centre point of much the play. Critics argue that hamlet is being a concept somewhat realised though hamlets devotion to his father. Across the play, hamlet remains loyal to his fathers memory criticising his mothers hasty remarriage, wherein he merely ‘seeming’ to grieve, dressed to respect the loss of the king without truly feeling any sense of bereavement. As Bradly concludes, hamlet assumes without any questioning that he ought to avenge is father.