I do backstitch (just 2 or 3 stitches) in the seam allowance, because the stitches come out when I tear the paper away.

No I don't backstitch, if there is another seam covering this seam.....I also find using an old stitch picker, upside down and using the back side - not the stitch picking side, run it down my stitching line, it will open the paper if you holding it up, it will break my seam free from the paper, and not cut the threads, then I don't pull out the threads and the paper comes off much easier.[ATTACH=CONFIG]571609[/ATTACH]

No, you always use a smaller stitch length on PP.