Hey, don't be so hard on yourself. Those are very good questions and as a newbie I appreciate every question asked and see it as a learning opportunity.
btw, in the one potholder I completed I only put the Insulbrite on one side. However, I did add another layer of batting. It's thick, and big I went with 8" x 10", but I don't get burned and it also works great as a trivet.
Take Care, Maribeth