The theory was formulated in the 1960s and 1970s as new information was obtained about the nature of the ocean floor, Earth's ancient magnetism, the distribution of volcanoes and earthquakes, the flow of heat from Earth's interior, and the worldwide distribution of plant and animal fossils.
The fact is loose control arm or track bar bushings can contribute to death wobble. Bent, or loose bolts, wallowed out mounting holes, and bent control arms can also contribute to your Jeep catching the shakes. To prevent this, keep an eye on your control arms and track bar.
Yes, you have a problem with the front brakes. If it's a shaking or a pulsation when applying the brakes, then there is a problem with the rotors and most likely will have to be replaced. If your getting a pullung or jumping to one side when braking, that would indicate a problem with the calipers or front brake hoses. The calipers bind and the hoses deteriorate internally and get restricted. Definately have it inspected by a reputable shop to be safe,