These look beautiful! The first one, it looks like maybe you were pulling the stitches a little too hard, but the others, you can hardly see the stitches at all. Good job!
If you use a fine thread (50 or 60wt) in a neutral (gray or beige) of the same value as the fabrics you're sewing, even whip stitches will be much less visible - and even disappear.
I think you'll find that after the quilt is sewn, quilted and laundered, the bits of stitching that you can see now will sink into the fabric.
