While I am not a professional pilot, my modicum of knowledge and private flying experience permits me to point out one thing - a large distinction between (a) the load-bearing structure connected internally and often within the wing to the wing box (if so designed), and (b) the skin itself.
Whether its load bearing or not, if there's a 'bolt' (or more likely a fastener) attaching some part of an aircraft to the rest of it, then it was put there for a damn good reason by the manufacturer and should be thus secured and maintained.