You've chosen an SP-intensive path. You'll hit 20M SP before you've maxed out your character's progression.

Early Shotgun Scout Skills, randomly sorted as to avoid debate (apply to Gal or Minnie):

• Advanced Lightframe (you'll need the CPU/PG and 2 high slots)
• Shield Extension V
• Biotics V
• KinCats V
• CardRegs III
• Core Uprades III (Shields, Armor, PG, CPU)
• Nades III (for M1)
• Active Scanner III (for A-19)
• Hives III (Compact & K-2)
• SMG Operation V (less kick)
• SMG Sharpshooter III (less dispersion)
• SMG Proficiency III (more damage)
• SMG Rapid Reload III

There are many, many other things you'll need but this is a good start. Don't worry about Dampening or Long Range Scanning until we see how 1.4 affects us. To answer your question directly, Dampening doesn't work at the moment due to LOS acquisition and predominant lack of folks running Scanners.

- Shotty