Both ratings are important. As a buyer you want to be a good business person! As a seller feedback is very important! A positive feedback from a buyer can help establish a reputation.
I always shoot a couple of shots from all of my regulated guns before shooting groups. It takes a bit of time if the gun has been sitting for a while for the reg to settle in.
As I said before, if you cut the ends of a cardboard box it will stop/slow down any splattering. Amazon stops by my house everyday thanks to my wife I always have boxes:)