how to get points: bumping in the car in front of you (SLAM), jumping cars combo x2-x3-x4 -etc, jumping out of a car before in burns (Close one), making another car burn (Takedown), driving on the wrong side of the road (Incoming bonus)... So you could get 20k point in about 15 sec just driving on the wrong side of the road and playing bumper cars.
the AI has the very unfair advantage that it can dispatch stuff to multiple places simultaneously, compared to a laptop trackpad... hard mode is way hard.
You can. In case your saves aren't loading, just reload the page.