U dont lower ur car for drag racing so u wont have to worry about scraping.
Your detuned Bilstein SLP shocks are meant for Road Racing with streetablility in mind so you'll probably want to put some Hal or Koni adjustables in there..

Relocation brackets were designed for lowerd cars to keep the lower control arms at an acceptable angle for launchs/torque loads on your rear end. When u lower the car the LCA's will point more horizontal when they should be at a slight angle.. Now with a car thats not lowered its ok as they will tend to improve launchs.

Adjustable torque arm by BMR is a good start too. The stock torque arm is like a rubber band..
And ummmm i think when u said "whats that bar going next to your drive shaft"...???? that bar is the Torque Arm... Very important piece of equipment.

Tires are the most noticeable part of this equation.. If u want Drag racing with streetablility then get a nitto drag radial.. will last u about 10,000 miles of driving but will hook better than street radials.

Start with LCA's, Torque Arm, and Tires...