Yes, the 3x5ft Snowmen Christmas Flag Decoration comes with everything you need to hang it.
Yes, this flag is made of nylon material which is indeed waterproof. This flag is specifically made for outdoor use and will withstand all types of weather.
low to mid 20's should get you swimming w/a 4ft. deck around the pool and the site graded.All is dependant on how big and the site and the xtras(auto cleaners etc.) The figure should be good for an 18x36ft. pool 3x5ft. deep on a reasonably flat lot.