I stopped prewashing my fabrics when I worked at a quilt shop and we cut and sewed out tops in-house. I like your suggestion for starching after washing though.
I've found that many of the reproduction fabrics have a lower thread count and pieces can shrink significantly when dampened in any way and then hit with a hot iron. I know that many teachers suggest starching your finished blocks and then starching them into submission to get the desired finished block size. But be certain your working with prewashed fabric before you try this or your block will shrink decidedly rather than grow. I love the crinkly look my unwashed fabrics and batting give me after washing and drying. Quilter's choice. I was given the tip to prewashed muslin backings first however since it tends to shrink disproportionately to your average quilting fabric.