Full damage in SR/S would be the thing that makes staying there difficult. Currently it’s way too easy. As you progress through the SR rankings things like ghosting and damage should change incrementally.
At S: No ghosting, full damage, no scrubbing penalties, no autodrive or resets. It would weed out more than half of the S drivers in less than few days because you would actually have to think about consequences when racing.
I would like to try that. It will not always work yet solves some problems. From what I deal with mostly:
Penalties from overtaking ghosted car resetting on track, no more resets no more problem.
Dodging people intentionally slowing down in the last corner or before the finish to scrub penalties, no more scrubbing, problem gone.
Dodging people turning on auto drive mid race, hit pause should be instant teleport to the pit.
However no ghosting would be chaos at first:
Following closely behind people, they make a mistake and clip the wall, GT Sport likes to bounce them across the road, impossible to avoid.
Same when they push it too hard and spin out. A non ghosted car in the middle of the track is a bad idea.
Damage can also be easily abused:
The biggest offenders atm imo are people cutting corners to get ahead of a group that's closely driving together. They'll bump into the inside car, which won't cause much damage and corrects their course. Yet the other car gets send into the wall ending his race or will take out someone else otw.
Next is those not adjusting their braking point behind a group. You can be careful not the hit the person in front of you. yet if the person behind you doesn't adjust they'll hit you, you hit the one in front, double damage, one in front goes of into a wall, race ending damage.
Then you have the intentionally rubbing other people off the track into a wall.
With damage the one getting hit is almost always worse off than the offender.
Yet I'm willing to try it as an experiment. I would probably do better in the long run as the reckless drivers won't be coming back while you're stuck behind the next group. It's too easy for them now to push it too hard, get reset back on the track at speed and catch up with the pack safely working themselves through corers side by side. Yet the person they take out won't be coming back either.