Hamlet's complex characteristic is hella confusing. I agree there isn't an obvious Oedipus Complex, but then again we never knew what Shakespeare really thought when he created the character of Hamlet.
Freud's theorisation on Hamlet's inaction staples onto the repeating references and Hamlet's obsession towards Gertrude's sexuality. His sitting of the play could also be theorised that Hamlet imagined himself as the one who had murdered Gonzago, as if I remember correctly he sat through it twice - reenactments of the affair and the murder. Also, his beginning of his obsession with Gertrude kind of mirrored in his attitude towards Ophelia - filled with deceit and wickedness, also perhaps an expression of his feelings of betrayal towards his mother.