re the rotate, it's a common problem with a lot of these jets and isn't necessarily a CofG problem... now that you have a higher power output it's probably even more pronounced due to the thrustline effectively keeping the nose pegged down that much more.

if you raise the nose gear slightly, and bend the mains forward a touch (both lowering the back and moving the wheels nearer the CofG then you introduce a better angle of attack and make rotate much easier. The technique you used is slightly risky in that you are popping up into a steep climb with no power momentarilly - the possibility is there for nasty things to happen.