The more focus points the more flexibility in picking which part of the scene to focus on. They also give the image sensor a better probability in identifying the right area of the scene to focus on in more automatic modes.
An optical viewfinder (or OVF) allows the photographer to compose a shot while seeing exactly what the lens sees. There is no time lag and they require no power - as opposed to electronic viewfinders which can drain battery life. They are also better in low light situations.