I like the pattern and think it could be a good project for a newer quilter. All the pieces are square, no triangles or other funny shapes with bias edges that could be challenging.
I mix prewashed and -- traditional and batik fabrics all the time. If you have one you are concerned about, wash it.
I love Bonnie Hunter, too. If you are interested in scrap quilts, you should realy take some time to explore her website, quiltville.com
I agree with the concerns regarding the thin or loose weave fabrics. If you use them, you will probably be sorry in the not so distant future.
Play with the colors and have fun! Enjoy your gift!