This won't work because LFS detects that you've unlocked it on an other computer and it locks itself as soon as you start it on your computer. You could use your mobile phone if you have one to connect to the net for a minute and unlock LFS.
Yeah, maybe GTR2 supports these but if it's not realistic then it's not very good, just another random factor in the physics. AFAIK iRacing doesn't even handle dirt on tyres.
Not so rare in autocross. The autoX editor is a unique feature which cannot be found in any other sims(AFAIK) and at its current state autox is not very usable as soon as you put a barrier somewhere near cars.
One of my teammates and I used to drive with a mouse setup like this for more than a year until we got a wheel and after a little practice it can be just as good as any other method. After patch Y it's not too healthy for the clutch because the throttle cut option is removed.
IIRC Before patch V LFS used pure synth engine sounds, but only Scawen knows this for sure. I think LFS sounds can be improved in LFS' current state. It's just not a very easy task to make a sound which sounds good on most computers and doesn't clipping like hell (like a lot of custom sounds on LFS forum). As I said I'm sure if Scawen would take the time to improve engine modelling and sound generating we could have very nice and detailed sounds but there are far more important things to do before the sounds get reworked.
LFS' sound system generates the car sounds from a single very short base sample. It runs this sample through a series of filters which simulate different aspects of the car's engine. You can access LFS sound editor by pressing Shift-A ingame. For example see attachment. (FZ5_test_sample.mp3 was originally a wav file, but you get the idea, it may be too short for some mp3 players).
@OP: I think if Scawen would spend some time upgrading LFS' sound system it really could provide high quality and very informative, dynamic sounds.