No, your car doesn't look that low.
What tracks are you hitting, and do you have video?
Less forward rake is better - yes. Keeping the nose higher puts your camber curve in a more ideal spot (it loses camber beyond a certain ride height), but also keeps your roll stiffness in check geometrically and actually will affect body roll to a degree (too low will actually enhance bodyroll). Also, going too low puts all of your suspension arms in a range they were never intended to travel in frequently, and the amount of bump steer you get may be more dramatic when compared to closer to stock height. That said, I am not saying lowering is bad - you want to drop cg. How far you go is also going to be determined by how bumpy the tracks you go to are. Or if you like to hit the berms, you can slam into those bump stops which wont help you any. So adjust accordingly.
Corner balancing is going to do just that - change corner heights to alter the weight distribution in the car. It's not that the front may be higher than the rear. But more like the driver side rear is higher than the passengerside rear (and the opposite for the front). This is to account for your driver weight and other factors.
As for the rear, I'd remove the rake and drop it down to where your fronts are. More stability out of corners. look at the e90 grand am cars also - they are setup where the rears are close to front ride heights (but fender gap in rear is like none, compared to the front where there is still some).
See pic here:
http://www.e90post.com/forums/attach...1&d=1248703937