I found the glad press and seal a real pain to get out from under my stitches. (I used some to when I did some hand quilting, so my stitches weren't exactly tiny) also I used a red sharpie to mark my quilting lines and my thread actually took on some of the colour so now it is pink
As for paper piecing use the cheapest paper you can find and use a slightly smaller stitch than normal, and tear carefully, it should all come out. If there are tiny pieces left they would wash out when you first wash the quilt.