As you said, wings and gears are probably the most important thing to change from track to track. There is no magic formula to find optimal wing settings; it's a matter of compromise between downforce and drag. The more wing angle you run, the more drag (but more downforce), and therefore less topspeed. You should just try different wing angles until you find what's faster for you, a starting point would be around 20-20, and try with less or more wing. The gap between front/rear wing angle is important too as it affects the downforce distribution, having more FW angle than RW will make the car more oversteery (especially after certain speeds like >130kph, because downforce increases with the square of velocity), and more RW than FW will make the opposite, a car with understeer tendency. A very fast driver with excelent control will like some more front grip usually, for someone who is still new, or learning, and has difficulties to control the car, an understeerish balance should be more desirable.
About the gears, make sure you have a decent 1st gear for the start, we use launch control in FSR (it's mandatory) and if the 1st gear is too long you will be very slow on the start. 2nd gear should be a bit longer than any other gear, to have a bit more stability on corner exit. Last gear should be adjusted from track to track, make sure you hit around 17000-17500rpm at the end of the longest straight, leaving some extra rpm for engine reliability/slipstream (overtaking). The other gear ratios should be quite well spaced, the rpm shouldn't drop below 16000rpm when changing gear. If it drops too much you will loose time due to limited horsepower on that range.
Cambers are usually a no brainer with this mod, run values close to max camber angles, or simply max.
Another thing you might need to adjust are ride heights/spring rates/3rd springs/packers. If you run a very low car, the car will bottom out, making you loose some speed (this is easy to check with a telemetry program like Motec). You have different ways to avoid this; increasing the static ride heights, stiffen the 3rd springs (they work when both springs on an axle are compressing, i.e. straight line), or increase packers (from 3rd springs), as they will limit the suspension travel.
Dynamic ride heights are quite important too when determining the aero balance, a very raked car (higher rear height than front) will give a more oversteery aero balance, and same applies for the opposite; lower rear than front will make the car very understeerish.
Also make sure you find a good brake bias distribution/engine brake setting that suits well to your driving style, this is something that almost every driver changes. If you loose the car on braking, you should move the brake bias to the forward, or you can increase the engine brake setting (increasing the setting means that you will have less effective engine brake, so the rears will struggle less).
Most probably I will upload a good and detailed setup guide soon.
