But ethics and morality ARE the barrier. Sure, you have plenty of scientists who wouldn't blink an eye before doing just about anything to a fellow human, but ethics are most certainly the explanation for why these legal restrictions and government regulations are put into place. Just about every core law and regulation put into place has a basis in an ethical judgment.
because the government is protecting me from me.
You act as if this is a bad thing? Personally I prefer it that scientists far more knowledgeable than myself are doing their best to ensure that I'm not brushing my teeth with lead-laced toothpaste, drinking milk that hasn't been properly prepared, helping to ensure that processes are standardized and providing me with convenient ways to know that I'm not unknowingly poisoning myself, etc. The FDA has done far, far more good than harm in this case.
I think if people want to do testing then they should leave the USA. Get out of my country, I don't want it to be legal for scientists to perform borderline unethical treatment on my citizens. Go to China for that, it's really that easy.