Holding the brake down and holding the tracs button for 5-10 seconds will turn off stability control. Be advised, the Mustang can go past the point of no return pretty quickly with stability control off. I recommend signing up for some auto-cross events to get better at driving the car with the the electronic controls turned off before assuming you can handle the car safely on the street without electronic intervention. Particularly while attempting "sharp corners at 5000RPM in 2nd gear"
I guess maybe the rule of thumb is that unless you are intentionally taking a turn so hard that all the tires are making lots of noise (insane on the street), the stability control should not be interfering. It only ever annoys me on the street when I am trying to get some throttle-induced rotation at low speeds. (say a right hand 90 degree turn).
If you are referring to just traction control: Yea, just turn that stuff off by momentarily pressing the tracs button.
2012 V6 Base. 6-speed. 3.31. Roush Wheel Hop Kit. BMR 38mm Front Swaybar. Camber Modded Koni Yellow Struts. Linear Steeda Sport Springs. J&M Camber Plates. J&M Panhard Bar. Airaid Intake. 93R Bama Tune. BBK Ceramic Shorties. Carbon Fiber Trac-Lok w/ Finned Cover. Hawk SR pads. GT Rotors. Spec Al Flywheel & Stage I Clutch, 18x10.5 ET38 Enkei PF01 Wheels. 285 30 R18 RE-71r tires. Boss 302 Radiator.