1. Displacement is a vector because it has both magnitude and direction:
A vector possesses a direction (left, right, upwards, downwards, frontwards, backwards, etc.) and it also has a magnitude (how much it moved to a certain direction).
2. I would say the reference points is the point from where you view and analyze things.
3. B. distance traveled is the same thing as saying how much something traveled, which turns out to be the magnitude that has been traveled.
4. Normally, the plus sign represents something that traveled to the front or to the right and the minus sign represents something that traveled to the back or to the left.
5. Yous should always communicate the reference point from which your results where obtained because not always the reference will be the same and depending on the reference points, results can change a lot.
6. First circle: Magnitude; Second circle: Direction. We can conclude this just by looking at the statement from the first question.
7a. To specify the direction of the store, you could say three blocks to the left, right, etc. so that the viewer knows where to go when looking for the store.
7b. I do not see how this one can be improved since it tells us exactly how we should find his house. But you can change "north" for something life "to the right" or "to the left" because not everybody knows where the north is.
7c. I also don't see how this one can be changed since all the information is displayed clearly. But you can change "west" for something life "to the right" or "to the left" because not everybody knows where the west is.
Hope it helped,
BioTeacher101