No, because I don't want to pull out the basting once I'm done. Call me lazy, but if I can, I eliminate as many steps as possible or consolidate the steps. I will pin through all 4 layers--suit fabric right sides together with the lining on the outside (this is wrong sides together with the suit fabric)--and sew that in one pass. The layers would be lining, suit, suit, lining.
2. When you're doing the elastic around the leg openings, do you pull it at all or just leave it relaxed?
This will leave you with a portion of the elastic that is smaller than the remaining back leg opening. This is the part that covers up the fullness of the backside. This is where you will STRETCH the elastic to fit that space. It ends up being any where from 1-2" shorter than the fabric.