I love paper piecing. I use a very short stitch length. So short that the paper almost falls off when I'm finished sewing. I use an old Singer to paper piece and the stitch length can be set at 30 per inch! I have no idea what that length was used for. You started with the best paper. Everyone loves vellum paper for piecing, if you haven't tried other papers then you will probably go back to vellum. Just be sure it's the thin vellum, like tracing paper.
I stitch about 1/4 inch past the end sewing line and have no problem with the stitches raveling but once again the tiny stitch length is the key.