Still reading through the thread but have some comments and concerns
Of note, while I let my license lapse, I was at one time a state qualified private investigator. Doesn't make me a super expert but at least know some of the basics.
First, this case reminds me a lot of the Norfolk Four case. I was in the navy and just can imagine myself having been in that same situation. As such, I can transfer the case through their similarities and think I can get a personal connection
Are there any comparable cases where there was a murder involving multiple assailants where they successfully remove the traces of all but one person? Can it actually be done in a short time frame? Make most sense just to clean it all up.
Second, I can remember a case of fraud on a TV program years ago. A woman worked at a DMV (Department of Motor Vehicle), created ID of various people, and then would pose as them and make huge purchases. In one case, the woman who's identity was stolen went to try to get information and challenge the charges. When the clerk was asked to identify, of course she identified the women who challenged the charges and she ended up going to jail. With how much Knox's pictures have been splashed around, I would trust no person stating they saw them. It is just too easy to manufacture such things in your own mind.
Third, I was reading a website which was one that believed Knox is guilty. It had written something along the lines of "There is substantial literature about false confessions, but it is difficult to find any examples of cases where an innocent person made a false accusation against another innocent party."
Witch trials anybody? Seems like if they make statements like that, their research is pretty shotty.
As far as I can tell, none of these people have the first clue about any aspect of criminal investigations. They can't tell good evidence from bad, and they can't tell good police work from bad, which is why they cling to the belief that there is a case against Amanda and Raffaele.
You mentioned the Norfolk Four, the history of which can be summarized as follows:
Suspect 1 (Danial Williams) confessed, naming no accomplices. But the crime scene DNA didn't match Williams.
Suspect 2 (Joseph Dick) confessed, naming Williams as his accomplice. But the crime scene DNA didn't match Dick.
Suspect 3 (Eric Wilson) confessed, naming Williams and Dick as his accomplices. But the crime scene DNA didn't match Wilson.
Suspect 4 (Derek Tice) confessed, naming Williams, Dick, and Wilson as his accomplices. But the crime scene DNA didn't match Tice.
And then eventually the guy who really did it, whose DNA matched the crime scene DNA, told someone who reported it to the police.
So, people who falsely confess do incriminate others who are likewise innocent, depending entirely on what the police want to hear. Anyone could come up with a long list of cases.
Interestingly, Alan Dershowitz has been spouting this falsehood of late. He has kicked off his shorts and climbed in bed with these people and he is having lots of fun hating on Amanda Knox. He assures the public that she will be extradited to serve her time.
As for the selective clean-up, it would be unprecedented as far as I know, but the point is moot as the crime scene photos show no evidence that any clean-up took place following this messy and disorganized homicide.