Plenum7, you have speculated on the degree of detachment between the writer of the note and act of murder/kidnapping, it is almost as though the writer is not aware of the murder, suggesting that perhaps the writer of the note and the kidnapper/murderer are not the same, that the note was written first and murder was not part of the plan. Pardon me if I am not clearly understanding your point and this is not what you are saying, I just wanted to give credit for this line of reasoning.
The idea that the note writer is not aware of the murder is a very interesting point. Along these lines, I wonder if the housekeeper was indeed involved in the plot in an effort extort money from the Ramseys.
She would have had access to the home previously and keys to enter on that night, knowlege of Patsy's handwriting, etc. She could have taken the writing pad/pen home and completed the note. It would have been easy for her to get these things out of the house undetected and she may have had knowledge of JR's work bonus, thus the amount of the ransom. Then the person(s) who were supposed to have done the kidnapping part of the plan could have easily slipped in with the key, remained in hiding until the Ramseys returned home that night, left the note downstairs upon grabbing JB. But in the process of trying to get JB out of the house quietly the plan was foiled when JB put up a struggle, the "gentlemen" used too much force to quiet her and killed JB. Or maybe the struggle came as they used force to try to rape JB.
I have also often wondered, as others have suggested, if the discovery of JB by JR when he went in the cellar was the first. He and Fleet may have found JB somewhere else in a more distressing position (or maybe the housekeeper was called in from a car waiting nearby after the others had killed her) and in an attempt to clean up the body/give JB some dignity before Patsy and everyone else saw JB, someone replaced her soiled panties, pulled up her pants, fixed her hair, etc.
