what other themes do they use besides the major ones

I'm not sure what you consider the major ones to be so I'll run through a few.

Revenge- the nature of vengence. Does it exact a price on both people?

Ghosts- Good /Bad ? Sins of life.

The afterlife- What happens after death? Is it better to suffer (slings and arrows...) this life or move on to something worse or better?

Hamlet crazy or not? This is of course the big question throughout the play. How do we define "crazy"?

Death- the nature of death.

Forgiveness- Can Clauduis be forgiven yet retain th profit of his crimes?

Okay, I could go on but I'll stop now