JMO8778, unless I'm mistaken the pineapple was pre-cut, purchased that way by PR at the local grocery store. So nobody had to cut it up for her.
My biggest problem with the BR theories is the question of timing. If BR and JBR woke up during the night, went downstairs and ate pineapple, then you have the same 'bugaboo' you have with the intruder--they had to be awake and playing around for two hours before the murder took place.
OTOH, if JBR ate pineapple before she went to bed (around 9pm or so) then what? BR wakes her up, takes her to the basement etc.? And when exactly does all this happen? It couldn't be earlier than 11pm, both by the pineapple evidence and the fact that the R's didn't go to bed till about 10:30 at the earliest. So, say the 'fun and games' start around 11, and JBR is dead by midnight. Then what? How do the R's find out about it? What time is it when they start all the mad staging?
More importantly, why, in all the staging of JBR that then ensues, do they leave the garrotte, if BR really was playing games with JBR? They had time to write the war and peace of ransom notes; why not burn, bury, or otherwise destroy the garrotte, and make JBR's death look like the work of a 'small foreign faction' instead of a creepy pedo?
The BR theories, to me, really don't add up.