In all likelihood, under the terms of your liability insurance, you have the duty to report an incident to your carrier. Failure to adhere to the requirements of your policy could have adverse consequences for you. I am not an attorney in Illinois so I can not say for sure, but you might have a legal duty to disclose your policy information where there has been an auto impact.
The fact of a misdiagnosis does not necessarily give you a viable medical malpractice claim. Such claims are comprised of a clear deviation from the standard required of the physician and a causal connection to real damages. The existence of a deviation must be established by a medical practitioner in the same area of medicine as the physician who might have been negligent. It would be advisable to speak with an attorney who is well schooled in such matters. I have handled many medical...
Malpractice is defined as an act or inaction on the part of the physician which deviated from the standard of care adhered to by practitioners in the same discipline where the deviation proximately caused damage. The determination of whether the facts in your son's case constitutes cannot be made by a lawyer - only by a physician with appropriate expertise in the sake discipline. An expert physician would need to review all the pertinent facts and records and make the call.
I do not practice in NY, so you need to consult a local attorney. In most states, if a liability carrier fails to settle claims within policy limits and you can show that the failure to do so was in bad faith, you may have a claim against the insurer. You do not control whether a case goes to trial if not settled however.
The simple answer in "no". You may not use another's trademark, copyright or image for a commercial purpose without permission, which in most instances means having entered into an agreement with the owner of the interest.
Depending upon the coverages in his auto insurance policy, your brother might be entitled to recover damages to the car and for some increment of medical expenses. The liability portion of his own policy would not be applicable to his own injuries.
The answer to you question depends upon the language in your brother's will. Given your characterization of the will, it is likely that the heirs of the deceased brothers and sisters share in the property.
You are entitled to the fair market value for the vehicle. You might be entitled to punitive damages. You do have a potentially problematic issue if you settle with the insurance company without guidance on the release document the insurance carrier will send you. You should consult an attorney prior to agreeing to any settlement with the insurer.