I would say to try using Reik's, David's or mine then without editing the setup (haven't tried others), I find them all fine and none bottom out even high fuel in au rouge don't think going to 5th would make it stop hitting ground , just make you slower, so even tap of brakes an lift in 6th you should be fine.
Also you may struggle to take au rouge straight from pits as tires aren't that warm, I always do a outlap so you maybe be fine after a lap, but I think your steering may be to sensitive or maybe just steering to much at that point, I let the car drive au rouge mostly and I just tag along and steer slight where ffb takes me.
Way I take it I try to take it straight as possible I get half car over first kerb slight move wheel to right and just miss right kerb(this usually makes me crash if I hit this kerb) you maybe just need to avoid this ? I can ride kerb top of hill on left, but I think fastest and safest is avoiding those 2. I only move wheel very little id say my hand isn't passed 10 o'clock for the right.
I use 270 degrees with 17 to 19 lock here, sometime a lot of lock can make it extremely sensitive. If you think ffb could be taking part in it maybe you aint feeling the other parts and clipping, try lowering ffb/steering force etc see if can let you react also.