While directly exerting your will can work for control in dreams, there are easier ways. From what I've heard, expecting things to happen works far more often for most people than simply willing it, especially when you give them some sort of cause, instead of having them just happen. For example, opening a door and expecting the scene you want to be on the other side works pretty well for a lot of people. If that doesn't work, try a different method, like walking around a corner, or spinning in place.

For your second problem, perhaps you could try getting up a couple hours early the day before, so that you're tired enough the next night to sleep those extra hours. Probably not the best solution, but it's the only thing I can think of now, and perhaps worth a try.