lol don't panic
I'm not sure about the flat spot between 5-6k rpm, is the car completely standard? Generally if they're standard, the WRX doesn't have much puff over 6000 rpm anyway as its held back by the exhaust system i guess (3 cats as standard).
On the suspension, do you still get the rubbing noise all the time, or just when cornering? Or did it happen as you hit the bump and then go away?