Welcome to the Quilting Board!
Wanda, GF Bisquick doesn't have any shortening like the regular does. You have to add your own.
Yes, you can use butter and less salt. It's a whole 'nother thread, but sea salt is healthier than regular salt, IMO. I have never baked with kosher salt and I don't make dill pickles any more.
Plain rice flour thickens well, too. That one surprised me.