I suggest that the lack of GRAB & RUN with JBR was due to the kinappers intent to also get Mrs. Ramsey that night. The rope in the spare bedroom, where Mrs. Ramsey slept while sick was the expectation of the sleepers activity that night.
I also suggest that the SLEEPERS had entered the Ramsey house previous of 12-25-96 and so lifted the paper and pens used in the note.
I also suggest that things were changed or left in the house and on the property as a religious required Muslim WARNING of the coming event. I contend the Ramseys never saw the WARNING!
The Muslim terrorist would also be going through purification rituals and testing ALLAH for a SIGN of their act being Allah's will.