Great lists...depending on if you applique...I always bring fusible web for fusible applique, and freezer paper (for mock hand applique by machine). If I am going to do some machine quilting, I bring along the paper I use for that (I use examining table paper...have a friend who orders it for me). I always want to make sure I have scissors for cutting fabric and for cutting paper.
Keep the ideas coming!! Not good to leave home without the machine foot control/cord...but my experience has been that if almost anything else is forgotten, there is someone that has what you need and are always willing to help out.