I have done hand piecing with the cotton covered polyester "general purpose" coats and clark dual duty thread and that worked well for me.
I do/did backstitch about every 1/2 to 3/4 of an inch while sewing the seams. i also used 1/4 inch seam allowance.
I used a single thread in the seam.
In my opinion, "quilting thread" is too thick/heavy for piecing seams of lightweight ("regular") quilting cotton fabrics.