Bearisgray, your mother was right. Mercerized cotton thread is stronger and less linty. For many years it was the best thread available to quilters. Now I use Glide thread almost exclusively. It's polyester, thin, strong and has very little lint. It also comes in a great array of colors.
For fabric on quilts I use cotton. On art quilts, like rryder, anything goes. Sometimes I interface polyester sateen to help it behave and limit ravelling. On art quilts I often use Sulky rayon thread because of it's beautiful sheen, but I don't use it for piecing or longarming because it's not strong enough.
For batting I generally use Warm & White on art quilts, and if they're large, an additional layer of felt to help the quilt lay flat. Sometimes I interface the backing, too. On bed quilts I prefer polyester batting because it's lighter.
Bearisgray, thank you for another interesting topic!