Reading the forums is fascinating, but highlights why the mystery will never be definitively solved. There could be incontravertable evidence and some of the 'bigwigs' would tear it to shreds!
The problem is that people (like you say) are looking for the cleverest answer, rather than a simple explanation.
Anyway, moving on to the Policeman theory again, it's interesting from the Catherine Eddowes inquest testimony of PC Edward Watkins and Kearley & Tonge Nightwatchman George Morris:
Watkins - I ran across the road to Messers Kearley & Tonge, the door was ajar, I pushed it open.
Morris - The door was knocked or pushed. I was about 2 yards from the door. I turned around and opened the door wide and saw Constable Watkins. He said "For Gods sake mate, come to my assistance". I said "Stop till I get my lamp".
Whilst Morris looked for his lamp, Watkins noted the time as 1.45am by his own watch. Inquest testimony continues: -
Morris - I immediately went outside. I said "What's the matter?". "Oh dear" he said "there's another woman cut to pieces". I said "Where is she?". He said "In the corner". I went over to the corner and shewed my light on the body.
Morris then blew upon his whistle and immediately left the Square to look for help via Mitre Street, heading towards Aldgate. Watkins stayed with the body, conducting a brief inspection best he could under the poor lighting conditions. He noted that her clothing was filthy and, upon her chemise, he also noted bloody fingermarks.
PC Edward Watkins remained with Eddowes until the arrival of City PCs James Harvey (964), Holland (814) and latterly Dr George Sequeira
By 1896 PC Watkins had retired. In 1901 he was living at Rush Green, Beacontree Heath Road, Romford, Essex with his wife and a servant, 54 year old Jessie Fowler of Hull.
I find it odd that he 'ran' across the road to check a door that was ajar when he knew the Warehouse had a nightwatchman.
I find it extremely odd that he only asked for help AFTER Morris, the nightwatchman found him (there's no idea there how long PC Watkins was with the body - although Morris' movements were apparently very well known)
I also find it very odd that it was Morris (according to testimony) blew his whistle and raised the alarm, rather than PC Watkins. Watkins was left with the body, and had plenty of time to set the scene or hide evidence.
Also, it appears Watkins had previous for having naughty-goings-on whilst on duty (many years before - but how often would these women come forward to complain?)
Watkins appears to be very much dismissed as a suspect, but doesn't the testimony seem very odd?