humidity (whats that????) has a lot to do how paint drys. if you're in an environment that has lots of humidity, it will take longer for the paint to completely dry on the surface.
same strap system, try to glue the sections that are currently velcroed though. but that's a personal choice. doesn't really matter.
can use anything on the inside of helmet, hard hat liner, foam, football helmet padding, baseball helmet padding, duct tape, etc.
you can get small pc fans at Radio shack, or ebay, or local electronics store.
the boots are normally the same. however you can get away with similar boots as long as they meet whats listed in the requirements section at the top of this site.
You can get the CABBOOTS versions, which at the moment are the best and most accurate, and replace the soles with Vibram Soles, which has a more aggressive tread pattern, and a bit more sand-trooperish.