You can hand quilt any way that is comfortable for you. Consider looking into how sashiko quilting is done. Rather than rocking the needle as is commonly used in hand quilting you pleat the fabric onto the needle accordion style. Sashiko uses a much longer needle, which sounds to be more comfortable for you. This style of quilting doesn't use a hoop. Of course you can use a milliners needle. Your stitches may be larger than traditional hand quilting, more like big stitch quilting, which usually uses a heavier thread than your Mettler but I am sure it will work just fine and because the project is a wall hanging you don't need to be concerned that your stitches are on the larger side.