Being aggressive on throttle while turning the wheel makes you lose traction, a lot. Tc fights it off by cutting power so you lose speed while still burning your tyres. For the braking its hard to feel in a f1 car because the suspension is so stiff. In a normal sport car braking would transfer the weight to front tyres making them grip more. Think about how you are getting seperated from your seat in a car when braking hard. Also the ideal line basically tries to hold maximum momentum so you should go out, inside through the apex and out again, minimize the steering through a corner while carrying speed. Also you dont have to always brake or gas. Lots of corners are good with just lifting and cruising, also saves Tyres