Maddie was abducted by a UFO that night. Now prove me wrong. God exists. Now prove me wrong. Faries exist. Now prove me wrong. Middle Earth exists somewhere up in the night sky. Now prove me wrong is how this argument goes...
yadayadayada. You need to provide proof Sir Blonk. You haven't - where is your proof? This is lead hat with layer of plutonium time(just in case you want blow up your own head!).
Some theories do not need to be exhaustively researched, because logic and probability can be used to narrow the search. You bring up some interesting points like for instance the photos that the McCanns provided on a DVD, but really this is the job the police to go and get this stuff if they are suspects or believe the info could be useful - it is not the McCanns job. Like for instance in David Payne's rog when he asks for the mobile phones and ensures he will get them. How do you make the jump from cherry picked photos provided to PJ at the start of the investigation when they were not suspects I might add to a week long alibi for Madeliene?