Slip and turn, the "creaking" noise you hear over the wing will be from the air conditioning ducts and/or filter/coalescers, not the fuselage. Someone just needs to tighten clamps or realign things a little.
For the non engineers here, the crack is a longitudinal crack, which means it is related to hoop stress caused by pressurisation. If it was anything to do with landing stresses which for those nautically knowledgeable induce "hogging" stresses, the crack would have been lateral, not longitudinal.
I am wondering if we may be seeing the results of a pattern of behaviour involving the supply and fitting of defective fuselage skins and doublers?
From 2005:
Frequent Flyer? Read this. Boeing Whistleblowers Say Planes Must Be Grounded