Don't run uphill, there's no running uphill in baseball, and yes, there is a difference between running uphill and flat ground.
It won't make you throw harder unless you have obvious lack of strength. Ask yourself how much strength does it take to throw a 5 oz baseball?
The right work outs can help you practice longer, improve heat-tolerance, help you mentally and decrease your chance of injury, which allows you to pitch more (giving good mechanics), which equates to more velocity.
While I do prefer to interact with people in a gentle manner... I'm also not at all opposed to establishing my dominance in a reign of terror.