Can I humbly suggest that the zooming in the key editor needs work. At the moment (1.5) it's "doing what I say, not what I mean" - translating my finger movements into zoom and requiring me to be very specific with how and where I move my fingers. What we need is for Cubasis to "do what we mean, not what we say". Just take at look at the zooming in Garageband - the concepts are exactly the same, but Garageband seems to translate finger movements into meaningful zoom.
Hope this make sense.