I have 2 embroidery machines, and using the hoop I would only do quilting a block at a time, or maybe a strip [ quilt as you go] With a whole quilt, what does one do with that roll of quilt under the throat area when you get closer to the centre, too much bulk. I would have to do it freehand.
Yes Juanita, you can quilt all three layers together in the hoop, you may have to loosen the tension a bit, do a test block first. You will not need stabiliser. The length of your stitches will be governed by your quilting [embroidery] design, not your machine. That's decided by whoever digitised the design.