1. Sometimes if you press
1. Sometimes if you press the start button too quickly after pressing the brake pedal, or if you don't press the brake with enough pressure, the car only goes into ACC mode. All you have to do is while it's in park, press the brake and hit the button again.
2. It's likely that the ICE was recharging the battery. When the car is new the shimmy when it starts to recharge is pretty noticeable. It almost feels like the car is downshifting when it starts to shunt some power to the generator. As the car breaks in, it should reduce to a slight rumble.