The at fault party is responsible for all treatment arising from your accident. If you have a pre-existing condition which was already healed, then this is a new injury as far as your claim is concerned. Hire a local lawyer. Best of luck.
If she is driving your car and has an accident and she has no insurance then you will be sued and will be held liable to the plaintiff. The difference of using her car vs. using your car is that most likely you will have higher limits to protect others and in case that she is hit by an uninsured driver, you can make a claim against your own insurance company and get the higher limits. Visit my guide on Avvo and read about being hit by an uninsured driver. Best of luck.
Unfortunately, my colleagues are right. NO damages no recovery. However, you can write to the company and complaint about their quality control and ask them if the tooth belongs to one of their employees or an animal. Best of luck.
Yes, his money can be used to support his child. He would be best served if he hires a family lawyer to help him set a court order and take the child support out of the equation of the games played by the child's mother. Best of luck.