There is no way to zoom out further, I am sorry.
Because of this I strongly recommend moving the keys that direct the camera to a very easy to get spot, and get used to using them exclusively... in fact, turn off edge-panning, and increase the camera pan speed a lot. This will improve your ability to look around frequently during gameplay, despite having a limited field of view.
I should note that widescreen displays see a larger portion of the gamefield than narrow ones; they see more to the sides. Because of this, attacking from above or below is often more effective than from a side, as the vertical view is fixed and limited, but the horizontal is much greater.