If a fabric is wonky to start out with, I am not apt to use it in a quilt. I may use it to practice with... or give it a wash and dry to see what it does and then use it in a utility quilt that I know my grands are going to use, abuse and love to death in a couple of years anyway...
I starch for ease of piecing, it helps me keep from getting ripples in my borders, and I am more accurate with my rotary cutting too. I don't starch til I use the fabric, but do store it afterwards still starched. I have not seen any of the bugs in my house that seem to like starch, and I do look from time to time to see if this is attracting them. If it ever does, I will start storing those fabrics in plastic bags.