Ben,
You don't have to set the hook into the belly, some guy's like to. I dont usally impale the first hook when using a stinger I do impale that on because it tends to catch weeds if you dont. On a smaller bait 6"or< I dont add a stinger because even a 2lber can eat a 6" bait but you may want to experiment w/ that. In the end it is just preference trial and error type stuff.