Problem with metal roof fasteners.

Hello all. I recently bought a house (simple gable roof) with a metal roof, and I discovered a problem that I absolutely did not expect. The roof has been in place for a long time, and the fastener's washers have deteriorated from the UV and summer heat, allowing moisture to wick down the shank of the screws. This has deteriorated the wood that the screws are trying to hold on to. The screws absolutely don't hold much at all anymore. Luckily it never gets windy in this particular microclimate my house is in! I have two possible solutions. One is to place a new fastener 3 inches above each existing fastener, and applying sikaflex to the existing fasteners as a sealant against water. The second possible solution is to remove all the roofing and then replace it using a 3 ft starter course and cutting 30 inches off the existing metal panels so I get a 6-in overlap over the 3-ft starter course - that way all the holes in the existing metal would be over undisturbed plywood and the screws could get a good grip. The first method would be far easier than the second method but I don't like to rely on sikaflex. In either case I would repaint the entire roof. Please, any better ideas out there?? Thank you so much!