We don't know if you need a rebuild yet, and even still, that'* not affecting your boost. Please go through the troubleshooting that I previously linked you to.
A little metal flake can be normal. We'll come back to that.
Start the car and idle. Pull the vacuum line off the top of the BCA (round cylinder on the front of the charger). Does the arm move fully? Put it back, it should go all the way back. Full travel. If you want to know what full travel is, you can actuate it by hand.