Themes would be: uncertainty of death, procastination, pretty much the underlining thigs or the factors that make up the subplot of the play. Uncertainty of death is a big one in 'Hamlet', seen in the famous 'To be or not to be' speech.
Also christianity and suicide- 'that the Everlasting had not fix'd His canon 'gainst self-slaughter' (ACT I, SCENE II, lines 131-132)
Values are like...hmmm, I suppose loyalty as a big one. Such as Gertrudes lack of it. Hamlet himself says 'a beast that wants discourse of reason Would have mourn'd longer', pretty much saying that a beast would have had more loyalty than his mother, who married his uncle not even 2 months after his fathers death.
So trust and loyalty, definatley now I think about it, as Claudius' treason is also looked upon.
Hope I heped