Cop103 you mention many interesting things but surely even a first year metallurgist could tell the difference between a thread that has failed through looseness (chaffing and wear) and a thread that has suffered sudden shear overload? The latter would have rolled over thread crowns etc.
You are very cynical of the investigators but I cannot believe the NTSB and Nigerian AAIB would ever falsely manipulate evidence. Are you falling into the trap of trying to make the evidence match your personal theory?