As for the belt issue I cranked my tensioner as tight as I could get it and ran the largest pinion I could put on it and installed a silver can motor I had laying around and put the thing in a closet and ran it for 2 days on 2 volts with a fan on the motor. The belt loosened up very well and the car is very smooth it is as good as my xxx-s it is worth the effort. Then I took all the bearings out of the car and soaked them in motor spay for a while and let them dry out and lubed them with some light bearing oil they became very free. I know this is alot of work but it increases the potential of the 04r very much. I run my 04 against any other touring cars and compete very competitivly with it.
For a high bite asphalt track I would try the stock setup with some sorex tires it works fairly well you can fine tune from their........