Welcome.
There's lots of techniques and opinion on acheiving "finished"
As to back. For years I loved using the leftovers from the front and creating an art statement for the back. Now, most quilts are busy activities, wide back is fine. Since commercial longarmer's want back wider than front, there's plenty of backing to make binding.
As my life changes, the purpose of quilting changes and my techniques change to match my purpose for quilting.
I've stopped listening to quilt police who require quilting to their standards. I set my own standards and try to ignore the "rules".