Hey buddy, is this the RTR version I assume ?
I reviewed this myself for RACER and thought it was excellent. The rear brace is really the only must have I think though - on a race track maybe you can get away with it but certainly if you are playing and having a few jumps you'll need one asap.
I was going to make my own but ended up getting stu woods dad to make one and its great..
Diff oil - depends on your track maybe but I was advised by Jamie Booth to use 30k / 30k / 10k (front, centre, rear). This made things a load better and stopped it leaning back so hard.
Stone guards again - I got those before racing the truck and was glad I did as they can be called MUD guards too.
Youve got to cut the shell for cooling yes!
see in this photo
http://www.oople.com/rc/photos/crtracerreview/bigimages/hn20.jpg
Maybe even bigger than that. Also you can cut the side window (on the engine side) to make filling the fuel tank up easier.
For starting the car - I never made a hole but i guess you could. I now have a starter box and I think thats the way to go.
The shocks are a bit soft as they come, I think they need a harder oil but Ive not done mine yet - but yes definately wind the adjusters down a bit as it sits a bit low otherwise. My truggy is standard apart from the rear brace I think and stone guards etc - and its awesome on the race track, absolutely great.
I found the standard steering servo to be OK - the throttle was a bit weak on the brakes I found. But for my first race I moved the steering servo to the throttle, and put a high torque KO in for the steering.
If you are using the AA receiver pack then ditch it right away and get a 5 cell receiver pack, I have the Nosram 1400 in mine and it gives a lot more power to the servos and is a lot more reliable.