Keepsake Kitty Wall Hanging - In progress

I'm still deciding what the next step should be for the Keepsake Kitty Wall Hanging. The top is pieced, the backing is cut.

Do I want to use batting and practice quilting (which I'm still trying to figure out how exactly to do - and need a darning foot first)? Or do I just want to finish the project by adding a border on the edges of the front and back and calling my first pieced project "done"? I'm leaning toward getting it done since I'm itching to start something else and don't like unfinished projects hanging around!

But first, I need to figure out how to applique the kitty's tail! Hand sewing it did not turn out well since I didn't allow for a finished edge. I want to machine sew it on but don't know if it can be done without a darning foot. I've tried the darning plate that came with the sewing machine, but I cannot move the fabric with the general purpose foot down and the fabric is way too free with the foot up. (Again, a basic sewing or quilting class would probably be helpful!)

My piecing skills definitely need practice as evidenced by not-so-pointed corners for the corner squares! It would be helpful to know exactly where the 1/4 inch mark is on my sewing machine...