issi nono
You are correct, V2GA is commonly known as Approach Climb limit speed, the CRJ700 AFM lists it as:
Approach Climb Speed. Target climb speed to be attained during a go-around with one engine inoperative.
1.) Why is V2GA on the CRJ7 different to the V2 for climb?
As one is for takeoff and the other is for landing, you will find that the required gradients, configurations and thrust are different.
Mutt