Alright, questions I actually know the answers too! Or at least can recount my own experience :p .

1.My dealer required $1000 deposit.

2.All GM Card points and other discounts have to be used when the car comes in and final total cost is negotiated, and can't be used for the deposit !

4.The effective GM rebates and incentives are the ones at the time of delivery, so current offers are "meaningless."

Hope this helps!