Does Hamlet's ploy of pretending to be insane have any influence on Claudius? Claudius's reaction at the play Hamlet stages can be interpreted as the guilt Hamlet requires to fulfill his duty to his father, yet it can be argued that he might not have felt well and Hamlet was merely seeing what he wanted to see.
Further, why was Hamlet all of a sudden concerned with his own eternal damnation after he got the confession he wanted, albeit AS a literal confession? If Hamlet really wanted to carry out his revenge, couldn't he have lain in wait OUTSIDE the church to exact his revenge? Why did he chicken out? Did he ever have the courage to carry this plan out, or was he, in final analysis, a coward?
Clearly "The Mousetrap" upset Claudius because of its accurate depiction of his brother’s murder. Another nasty little surprise was Hamlet’s words of “See the nephew kill the king.” Was Hamlet threatening Claudius? Was it a mere slip of the tongue? Claudius couldn’t be sure, but he was experiencing guilt (not illness) hence his soliloquy in Act III.iii.
Clearly the melancholic, brooding Hamlet is a thinker, and his act to appear insane is a ploy to make other courtiers react as Polonius has as well as to have them let down their guards and reveal something about themselves thinking that Hamlet will either not notice or misinterpret what he hears.
When Hamlet espies Claudius at prayer, he has not suddenly become aware of his eternal soul as suggested. In his famous "to be, or not to be" soliloquy, for instance, he again contemplates the consequences of suicide, deciding against it since it is a grievous sin and
...that the dread of something after death,
The undiscovered country, from whose boum
No traveller returns, puzzles the will
And makes us rather bear those ills we have
Than fly to others that we know not of?
Thus conscience does make cowards of us all,...(3.1.78-83)
That Hamlet is conscious of sin is also evident in his contemplation of his mother's lustful haste to remarry and her "incestuous act."
As amy-lepore writes, Hamlet dithers and puts off his revenge for the very real reason that gaining revenge for Hamlet is far more complex than for the other characters in the play who are placed in their own revenge drama, such as Laertes and Fortinbras. For them, it is a simple code of honour which is rooted in family pride. For Hamlet, there is a definite moral problem. The Ghost demands a more ancient form of revenge in a Christian culture, yet the Ghost also talks about suffering after death and the pains of purgatory. Gaining the revenge the Ghost asks for would then send Hamlet to hell. Hamlet then is inextricably divided between duty to a Ghost who might be his father and obedience to his God. This explains the endless wrestling bouts with his conscience and his slowness to act - we can hardly blame him!
I'm sure the ghost did not approve of Gertrude's death, since he told Hamlet to take it easy on her in her bedroom after the staged play, and the deaths of all the other innocents were directly linked to Claudius' greed and ambition. The ghost most assuredly would not approve of others dying at his brother's hand as he did.
Polonius, of course, could be the one exception since his idiocy prompted him to poke his nose where it did not belong causing him to be picked off behind the arras. Ophelia, too, was a fragile one whose death might not be tied to Claudius except for the fact that Hamlet's behavior is directly linked to Claudius' murdering King Hamlet which leads to Hamlet's paranoia, mental instablility, and Ophelia's father's death...all of which push her over the edge.
My first impression of this play was, "Hamlet, DO SOMETHING! Lead, follow, or get out of the way." It drove me nuts on my first reading that this entire play was based on a character who couldn't make up his mind.
On subsequent readings, however, it becomes clearer that Hamlet needs to be convinced of Claudius' guilt. He can not bring himself to just go with the ghost's side of the story, so he sets up the play to verify what his father's ghost tells him. Once Claudius' actions proved the ghost correct, Hamlet knows that he can not kill Claudius while he is praying. Why? Because the ghost also told him that the ghost is destined to wander around forever since he died before he was able to ask for forgiveness and repent of his sins. Hamlet does not want Claudius to have time to repent. Hamlet feels that Claudius should also have to wander around forever, suffering as a result of the crimes he has committeed while on earth. Not to mention the day that he actually DOES murder Claudius--the fencing match with Laertes. Here, he actually kills two--one by mistake for which he apologizes, one with intent for revenge...not a coward by definition. His mother also dies in this scene, which is also revealed to be the King's plan, meant for Hamlet himself. Before Hamlet dies, he names a successor for his kingdom--quite noble and honorable. He would have been a good king had he been given the chance.
Hamlet does do much in the play, though I don't know why people think that he procrastinates. His plan is extremely well thought out. His revenge in the end is to cause the downfall of not just Claudius but all people who did nothing to prevent the events from happening.
I always wonder about the scene when Claudius is confessing his sin in the context you raised about Hamlet's father dying without confession. Shouldn't that have spurred Hamlet forward rather than rationalizing that, eh, he confessed so I'll have to think of something else.
Which as you point out, he did, but it was more a thing of chance (and Laertes' own quest for blood-revenge), ironically plotted by the person Hamlet was directed to kill. Goals accomplished, but due to his ruminations, at the expense of far too many people. One has to wonder what the Ghost thought of the final outcome?