You are forgetting that FI introduced a significant update in Britain, after Turkey and other tracks. In Valencia they ditched the Kers option and introduced much more sculpted sidepods etc etc.
2009 was a development race, look at Mclaren and Ferrari at the first couple of races.
And since when does FI have balance issues? the advantage they are having this year, is that the car is much better balanced (the VJM01/F8VIIC) was horrible in that department).
And one of the reasons why Fisichella is finding it hard to get to grips with the Ferrari.
But then again these are just my 2cents
The new Diffuser which is T-shaped (haven't seen that at any other car before).