] He does say to Horatio and Marcellus to pay no heed if, in the future, he were to put on "an antic disposition". This shows the idea was already brewing in his mind.

Yup.

] But, I think an arguement could be made that, after seeing the Ghost and retiring, the ghastliness of it all struck him anew and he became horrorstruck and agitated and went to Ophelia for comfort.

Certainly and that is one of those questions that a director must answer, When does Hamlet go mad? Does he go mad at all? Shakespeare being Shakespeare, I don't think there there is one answer to anything anyone does. It is all so emotionally complex - just like people. That is why his plays have lasted for centuries and have lost none of their interest. But that is another conversation for another day. Back to Ophelia.

] You believe he is putting on the first demonstration of his "antic disposition"... I can see that, and you may be right.

I think he is certainly disturbed by seeing his father, but he still is in his right mind. It isn't until later that he really starts to lose it culminating in the scene with Gerturude when the Ghost comes back to warn him to keep to his task. Once again, another conversation.... Where is that Ophelia?

] Perhaps it's my wish that Hamlet not appear to treat Ophelia even worse than I had originally thought that makes me shy away from it. ;-)

I don't think he does so intentionally. I don't think he has a clue of how deeply she feels for him since she has been continually warned against him. He has done all the work thus far. All she says is that he has given her many letters professing his love, but nothing about her returning them. Maybe she is being coy, but I don't think she is devious enough for that. I think she is purity and that is why she cracks after her father is killed.

Another example of Ophelia as a ruse is, just before he confronts her in the Get thee to a nunnery scene, he says, "Nymph, in thy orisons/ Be all my sins remember'd." To me this sounds like a plea for forgiveness for what he is about to do.

Later, in just before the play, he puts on a whole act for Claudius and Gertrude laying in Ophelia's lap, etc.

Just a thought.