in regard to the wandering, the chassis may be tweaked, especially if you have had a reasonable impact...
You can try loosening all of the structural screws on the bottom of the car to release the tweak.
Sorry I don't run on foam, otherwise I'd send you something. Are there any other drivers at your track that run the TC4? Check with them
It's a good car and although I have experienced some wandering due to tweak on my stock car, I also run a novak 4.5 and can hammer it straight as a die (it's when I have to make a corner that the trouble starts!!!)
Also, hold the car in one hand and go full throttle watching the front wheels. Sometimes they can wobble (perhaps from glitching in your electronics). That will make your car erratic.
Good luck mate.