As long as those game options makes the car easier to drive, IMO they are aids/assists in the game, it has nothing to do if the real life cars they are trying to simulate have any of them or not. That's why PD listed those assists to be player's choice to use, otherwise PD would simulate those assists like each actual real life cars as preset and can't be disabled.
That is also why I consider brake assist/ABS as PD approximation of ABS on the real car, it does not even behave like what ABS would do, more like a slider for how would the software would prevent wheel lock ups when braking, similar to brake assist in any other game/sim. It even stabilize the car under brakes unlike real life ABS could ever do, to get that, the real life car would need EBD/ESP, in which would still not be as perfect as in GT5.
Brake balance adjustment does not negates "stock" in GT5, as in online, even with tuning prohibited, BB can still be adjusted, while others can't.
I just wanted to know the fastest with aids and without ANY aids possible, but it seems moot now.
Just my opinion, nothing more.