Points for fantasy are fairly simple. We receive what the drivers do in the points standings.
For example:
1st place gets 46 points.
2nd place gets 42 points.
3rd place gets 41 points.
down to 1 point for 43rd place.
On top of those points we also receive points if our driver leads a lap and/or has a fastest lap
0.5 points for every lap lead.
0.5 points for every fastest lap.
We also receive points for the place differential of our drivers.
Driver starts 1st and finishes 3rd is -2 points.
Then we have the bonus points. 10 points for picking the winning manufacturer. 30 points for picking the winning driver (bonus pick).
Finally, if you pick a driver on the list that does not qualify for the race, then you will receive 0 points for that driver, as is the case with Gaughan and Hornaday. Then, you have Junior and Johnson whose finishing position was much worse than their starting position, which is why they received negative points.
Hopefully this clears things up a little.