The server is set to allow factory driving aids and auto clutch if I remember correctly.
The Auto clutch is to enable people to race with really old hardware.
All of this can be over-ridden by your own setup, I always drive with traction control off unless in a GT3 or something that depends on it.
ABS is generally dependent on the car - for instance with the Nissan 180sx mod I actually turn it on, because the braking is very different to my own 180 (which doesn't have ABS), so I tend to crash a lot when trying to drive like I do in my own car
Any road car that goes sideways will be faster with TC off, I tried the Mustang with TC at Okayama and was noticeably slower.
ABS is faster or slower depending on how good the suspension is normally.
For these I personally will be driving with TC off and maybe ABS on. You can drive as you please, it is not fixed on the server
Welcome to nocatu - glad you let me know your AC name, it will make importing the results much easier!