Trying to turn at a high speed will flip just about any car. Now you know what a traction roll is.
As far as the truck running at a hi rpm when it is upside down that is caused by a lean condition from the truck being upside down, all trucks will do this if they don't have a dual pickup tank.
It sounds like the brakes need to be adjusted. The manual should be able to tell you how to do that. If you can't figure it out take it to your local hobby shop and they should be able to show you how to do it or do it for you. According to the CEN website there are two shops in Little Rock that sell CEN parts.
There are a few upgrades that are almost required, they are the metal brake seat and plug, hi torque steering servo, and the radio.


rolland