Crafty Grandma, I have a question. How far apart were your quilting lines in the quilt that had the problem with a fabric shrinking excessively? It is actually unnecessary to prewash fabrics for shrinkage *if* your quilting lines are a moderate distance apart (probably no more than 4"). This is because, when quilted, the batting prevents any fabric from shrinking more than the batting shrinks. This does not apply when the quilting lines are far apart (say, 10" apart) because then there is a 10" expanse of fabric (more on the bias) that can shrink an inch or two.
Why do you rip? It's so damaging to fabric, especially on the crossgrain. There are rare circumstances when I will rip on the lengthwise grain for long borders (and when I do this I either trim off an inch from the ripped edge or make extra-wide seams, such as in a backing). However, I never rip on the crosswise grain. I simply don't see a need to do that.