Updated to V1.9.5: You can lower the rear further for the race if the balance isn't quite right for you. Just be gentle with the steering and in transitions to keep the rear in check. It's just a flaw of the car you can't quite rule out with the setup.

Race drivers always seek for the duality of physics: He/she wants traction. And Rotation. A good front end and a good rear. The truth is: It's all always there, but what the driver is unhappy with is laptime and corner speed. Always. The Audi has one of the best front ends you can find and it has good electronics, too. But with the big V10 in the back, there's a decent amount of weight that is trying to make your life harder. It provides good traction in quali and allows to slide the rear just about as much as you want. But in the race it will work the rear tires quite a bit and controlling temperature there becomes crucial.

Here on Zolder additionally we have the issue with the chicane, which compromises the setup a lot everywhere else around the track. The front end is always too good for the rear. On a mechanical grip dominated track as this the approach is a bit different. We removed rake but run stiffer springs at the rear to get the car to rotate. You will see that it drives quite nicely now, without giving you too many surprising moments. However both chicanes are very tricky, especially the 2nd one. Its very important where you slow down and where you maintain speed. An unloaded rear will easily start bouncing and snap.

Electronics:
TC1 on 2 or 3 for Q and Race feels best for me as the car allows you to actually work with the rear on throttle (The sequence seems to be 1, 2, 4, 5, 3, 6 ... and is mostly down to how much oversteer the TC will tolerate). I would keep TC2 low or off for Q but on 3 for the race.
ABS on 3-5 seems predictable. On this patch lower ABS might be better still. Try 2 if you want.

Adjustments (you dont actually need any imo)

• The spring steps are rather large
• stiffen front spring if braking into the corners is an issue or the car is generally too oversteery for you, yet its almost maxed out, so rather reduce rear ride height, or even lift the front
• add rear camber and/or toe for a bit more stability
• move BB forward if too loose into the corners. 
• adjust rear ride height for over/understeer by 1mm steps. Also consider raising the front as the downforce loss is minimal, which allows for subtle balance adjustments
• Raise the entire car a bit if you want more tolerance over kerbs, the car barely loses downforce with higher ride heights - however the weight travel will be more pronounced
• For lower rear tire temp you will have to shift the balance further. Lower rear ride height, higher front, stiffer front spring, etc. 

Driving

• into the hairpins you can be quite aggressive with the brake, the ABS will sort you out. Try a slightly diagonal braking line in the very last phase of braking for the hairpin 
• Onto the throttle don't just floor it in the slower corners, give the car some time (say, half a second) and it will thank you
• aim for late apex in hairpins, try to trail deep, immediate but progressive throttle, little to no coasting in tight corners, aggressive throttle in longer corners. early power is very crucial to work the diff and unload the front.
• Brake carefully in T1 and T2, and try to be on throttle before the apex already
• In the chicane hit the first kerb, but avoid the 2nd as much as possible. While you might be faster using the right kerb as well, the much more consistent line is using only little of it. You'll gain back during acceleration what others lose while bouncing
• In the 2nd chicane its important to have the wheels straight every time you hit the bumps
• track limits tend to be wide, use them!

LFM:
Just reduce fuel load to 45/49L. Balance should become even more neutral. Adjust rear ride height +-1mm to your liking. Most likely up by 1mm for medium fuel loads. Also worth experimenting with one click of spring on front or rear to get more over/understeer in general.

LFM License:
If the setups is still somehow under or oversteery, dont hesitate to adjust it one click at a time. Lowering the rear will make it more stable, as well as increasing the front ride height. The latter will also help improve kerb behavior. Ultimately you do not need a world record speed setup, you just need the license for now and to do 7 laps in a row without mistakes. So whatever reduces your amount of mistakes is a legitimate setup. 30 liters are more than enough for the 7 laps. 

Enjoy and leave feedback!