The sway bar is a front end item. Part of the main frame of the vehicle. It keeps the front of the vehicle in a line with the steering as you drive. If it breaks, then your steering will not be accurate and you can 'sway' out of lane, etc. Not safe at all. Ball Joints are connections made from one part to another. Think of them as your shoulder or knee sockets. They move according to the movement of the car and roadway, keeping the vehicle with a smooth ride, etc. They're usually packed together tightly with a rubber lining around them which contains lubricant. when the joints start to wear out, the lubricant leaks, and every movement of the car becomes noisy. If any break, you cannot safely drive the vehicle. It's all expensive repairs, considering parts and labor. But that's a lot cheaper than getting into an accident or getting stuck with a breakdown on a road 300 miles from home. I think you can draw your own conclusion to your question, right? Good Luck.