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.
Bear in mind that engine oil and transmission fluid also become darker after a while, so a deeper shade of red doesn't mean the power-steering fluid is bad. Before you jump at paying for this service, see what your owner's manual or maintenance schedule says. You probably won't find mention of changing the fluid. You should check the power-steering fluid reservoir monthly to make sure it has the proper amount and that the power-steering system isn't leaking. Reservoirs on many vehicles are the see-through plastic type, so you don't even have to remove a cap to check the level. Consult your owner's manual for the location of the reservoir in the engine compartment for help. You also should check the manual for the type of power-steering fluid that is required.