My first thought would be a Disk brake pad anti-rattle device.It should be made out some sort of shinny material possibly stainless steel.
On the question about the noise when turning the rear wheel. This has always been one of my concerns on my 06 S/W but after 35,000 miles I guess this has to be acceptable.Some noise can be eliminated by removing the clutch assembly(no special tools required) and cleaning out the dust(use air pressure) from the clutch shoes.Sand the shoes and the clutch drum.Not necessary to remove the drum.You will find a torrington bearing (needle type found in u-joints but larger here) in the clutch assembly.My experience has found this bearing to have the minimum of lube. Not that it needs that much but I use a little high temperature wheel bearing here.I also use 90 weight synthetic gear lube instead of engine oil in the final drive. Hope this helps. p.s. Install the belt in the same direction that it was removed.