A:
From the looks of this and how it's rigged, i'd recomend using a glass bead cinched to your line placing the depth of the rear lure to the depth you want it to remain (minus 7 to 8 inches for the lure length)... and the bead should add an additional tapping sound as well while the top water portion is at rest.
At least that's how I plan to set them up as i often fish shallows and shore lines as well as from shore.