In my opinion, what the biggest issue of the interface is, is that there is very little room for customizing it. There is practically nothing wrong with the options the camera controls give you*. Instead what I find irritates me most is that those options aren't arranged on the keyboard+mouse in a very practical manner. It is neccessary to change the position of your hand to get from camera keys to hotkeys and back, again and again. This, I think, comes from inefficient use of those keys and buttons.
For example in World in Conflict by Massive Entertainment you would order units to move by clicking. Pretty standard I'd say. If you clicked and dragged however you could also set the units facing and spacing(in case of infantry units or multiple units), thereby giving one button three related and often used functions. Also Zoom To Cursor, which was mentioned in the review, made camera work much more efficient as you could zoom out completely and then from the big picture zoom in exactly where you need to be with minimal effort and mouse movement.
Another approach to keys I know from ARMA which can detect the difference between pressing once, double tapping and holding a key or button, enabling you to have many different functions on very little keyboard space. Also using keys as modifiers could be used to make things more efficient.
Now these methods may or may not be applicable to CM, but certainly they can set an example of how efficiency can be achieved.
In this context I find it further irritating that I can't use the number keys, space bar or wasd keys(+q and f for some reason) for other things than the functions they were originally given as they will then perform two functions at once. This might be a bug though. Further it would be very helpful to have an adjustable slider to regulate scroll speed (+ perhaps the speed of other camera functions).
This game is much like eating raw chilis, at first incredibly painful, but if you've done it enough very pleasurable.
*(I say practically because I would prefer the Right-click-drag to translate mouse movement directly)