I'm one of those pre-washers! I prewash everything as I had a red fabric run years ago in one of my first quilts. I have bought tons of CT fabrics and found them to be great quality. I have also bought a number of their kits and prewash them too. They are quite generous in the amounts they give you - I've never been short - just be careful and don't make mistakes cutting out your pieces. They give excellent instructions showing you how to cut your pieces - you can see how much extra you will have left over. I really like that the kits I have ordered they give you enough to cut your borders in one strip lengthwise on the fabric. You don't have to cut crosswise and piece the borders.
I have noticed that CT solid fabrics seem to ravel a bit, nothing out of the ordinary from other solids. I wondered if the process of printing dyes onto the fabric with prints sort of "anchors" the weave and prevents some fraying. Anyone out there know?