Some nice ideas. IMO the crash, walk to pits and drive secondary car is something you do see in RL racing, so it might be a nice idea to have, but then again, would you really want someone running around the track like a loony when your racing? Also, not driving for 2 weeks is very long, and i know it would put me off the game instantly. I mean sure, i smash the XRR to smitherines and i cant drive it for a week, but i got all the other cars i can use, but i want the XRR. Just wont work.
Although, the idea is something that could be worked on. For example, you win credits for comming X out of X in a race. So say you come 1st out of 20, you win X amount of credits. Then when you crash, you cant shift+s and the car is all hunky doory, you have to drive to the pits and use your credits to fix the car, or fix it in the garage after / before a race. Same with any mechanical errors such as a fooked clutch. But i dont think any of these should be implimented untill LFS has a semi-realistic damage / failure thing.