Both are features that Uber can implement, but you can't cheat the market. At the end of the day, if you're just driving someone from point A to point B, you're competing with everyone else at the moment doing the same. As a driver, your client in this case is either Uber, Lyft, or another ridesharing service. If they add the ability to decline riders, I don't see how it would be used for anything else besides discrimination.