Recently retired Cubmaster here, so I'd like to chime in on the legality and cheating. The rules for axles and materials are usually set at the district level and most of the packs under them follow those rules. For my pack, you had to use the provided axles and wheels, OR BSA approved wheels. They recently started making colored BSA wheels and those were acceptable. I never saw a parent (or kid) trying to cheat in that respect. I saw a few cars that I very strongly suspected that it was a pre-cut body they bought, BUT we take them at their word for something like that.
My last year, we did an unlimited class where you could use any wheels, axles, materials, bearings, etc. The only limitation was the physical size and weight. In that case, these axles would be perfectly legal. Our car for the unlimited was made from aluminum and we turned our own wheels out of UHMW bar.
We had one dad who took his son to a championship race with a car they built with micro bearings and wheels that were thin as razor blades. Again, totally legal for that race.
The ideal setup for pinewood derby is when the child makes the car with his adult partner (dad, mom, grandpap, uncle joe or whoever) and learns a little more each year. 1st graders can't do all the cutting and polishing themselves, but should still be involved with each step of the build. By the time they get to 5th grade, they should be doing most of it themselves. I like seeing when they get creative to make the car run as fast as it can within the confines of the rules.
As I always told the kids, if you had fun building your car, then you've already won.