Due to hand issues, I am looking at short scales. Looking at the Mustang, although I see it has just one volume and a pickup selector, which seems to be a poor setup, since you can't blend the pickups. Also looking at the Squier Jag. How does that compare? Also, in the photo, it looks like there are two metal knobs (or something metal) on either side of the bottom strap knob. What are they?