Stomach ulcers are sores that form in the lining of your stomach due to erosion of the protective mucus layer. Bacteria called Helicobacter pylori or long-term use of nonsteroidal anti-inflammatory drugs, such as ibuprofen and naproxen, can cause this erosion and expose the lining of your stomach to harmful digestive juices.
Nothing good. Brake fluid is usually much higher density hydraulic fluid as well as different type than is power steering fluid. In vehicles with ABS systems it will damage sensors and seals, and in any vehicle it will result in spongy, poorly operating brakes and damaged seals.
drain and flush it quickly. Because its a power steering pump, it will cycle the fluid in the res. This will mix water with specially designed fluid for that pump, and could quickly damage the pump mechanism. Don't ask me how to drain and flush it though....