The locked door in Mary Kelly's room does seem to deviate from the ripper's desire to publicly exhibit his victims.
I didn't notice that desire. I just noticed a bunch of dead bodies that were laid out in a manner where they could be worked on. Being displayed for the public eye is purely conjecture and something I'm not buying... yet.
I always like to come to Joe Barnett's defense by saying that it's always been my strong impression that he and Mary Jane were not really split up permanently, but "on a break," and the fact that he still visited her and gave her money when he could are signs of hope, not despair. I think he's gotten an extremely bad rap over the years and was a fairly decent guy who never killed anyone.