Answer
No, no, yes, yes.
Work Step by Step
The y-coordinate of the starting point and of the ending point will differ between the 2 observers, so their determination of initial PE and final PE will differ.
The displacement is the same, i.e., the difference in heights, so the change in gravitational PE is the same.
They both measure the same final speed, so their determination of the final kinetic energy is the same.