Since you put the straps around the pad, you don't feel them at all. I have slept with the straps around me instead of the pad, when it was warmer, and I still didn't feel them. They're very thin. The whole thing, at least on the Golite quilt, is kind of fragile.
I can picture the shirt stay clasp. It sounds just like a garter belt. I would worry about the shirt stay things wearing a hole in the fabric of the quilt. But maybe you could sew on some small fabric tabs to put through the shirt stays. I'm pretty sure that would work perfectly.