The quality of your "research" isn't very good if you can conduct it and reach completely incorrect conclusions.
Technically correct. Factually irrelevant in this case. The Air Commerce act, Civil Aeronautics Act, United States v. Causby, Griggs v. County of Allegheny, Branning v. United States and many others established that in certain areas you may not fly below a certain point.
Federal Aviation Regulations (FAR's) have the force of law under the acts you cited. FAR part 91 states that over a congested area an aircraft may not be operated below 1000', over an other than congested area it may not be operated below 500'. It does not matter that an Indian tribe claims jurisdiction up to 20,000', they don't have it. The FAA owns that airspace, the tribe can claim whatever they want but it's not theirs to claim. FAR part 91 also states, and this is the part that overrides everything else, that "In an in-flight emergency requiring immediate action, the pilot in command may deviate from any rule of this part to the extent required to meet that emergency."
In other words, if you have an emergency you can do anything you deem necessary in order to safely handle the emergency. An engine failure in a single engine aircraft qualifies as an emergency under anyone's definition of the word.
It looks like someone more familiar with the law already explained to you how the court cases you cite are dealing with noise complaints and compensation for that, they're not relevant to the subject at hand. Your argument that someone other than the FAA can control airspace over an Indian reservation in the US is wrong and have been shot down in court every time.
I may not have done the "research" you speak of but my ten years of flying airplanes in the Navy and 23 years of civilian airline flying give me enough of a background to know you don't know what you're talking about.