Well, it's over now and I have achieved my goal to beat one of my friends, improving from 1:28,660 to 1:28,395 which is finally #510, but it was close though, I just beat him by 0,065 !
I think that this is not too bad for a 63 year old mediocre driver!?
I finally used Nowcontrol's Setup, mainly for what she (he?) said:
"...to tame tail end enough for my driving style without killing too much of the essential rotation and willingness to slide a bit...".
Well, I don't like the sliding bit part, but this Setup is the one where this car is sliding the least.
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So apparently my driving style and Nowcontrol's seem to be somewhat similar (even though I could never dream of touching his/her lap-times!).
AND:
I allowed myself to change the Final Gear from 3,600 to 3,700 which costs a bit of top-speed (which is not needed here anyway), but makes the car a bit more aggressive/faster in the lower gears, so you can accelerate quicker out of the narrow corners and step on the gas a bit earlier and stronger.
Thanks again,

it's 5:30 a.m. here and we still have 28 degrees, but this is one of the advantages of being retired: I can now play it the Vampire-style and go to bed and sleep at daytime... us vampires don't like the sunlight...!
See you all soon again on the grid!