A. The enthusiast is purchasing the vehicle. As long as he or she is following the rules of the road, and his or her vehicle meets the safety standards for the year of manufacture, there should be no problem.
B. It is up to each driver to decide what risk is necessary. It is a system you accept the risks of when you buy into it. Should you wish to reduce these risks, you should contact your elected officials. Once again, the lack of stability control should be a moot point when someone is driving legally. If there is a circumstance where someone has lost control, it is likely that broken equipment or broken laws were involved.
C. The enthusiast should not be driving at unsafe speeds on public roadways. Period. If they have done so, they will have to take responsibility for their actions. This is one reason vehicular manslaughter statues exist in many states. It allows vehicles to be classified as deadly weapons, thus making it easier to convict. Sadly, the people who can afford these vehicles can often afford a good lawyer and somehow get off with probation.