Controlling pan and zoom timing

I'm new to Rush, beginning to make sense.

Right now I'm working with wide still images. My goal is to have the left end of the image hold for about ten seconds, then pan slowly all the way across for twenty seconds, then hold for another ten seconds. I plan to add text at various points along this forty second timeline.

So far the only way I can see to do this is to load three instances of the image:

1. The image at the start point of the pan.

2. Then the pan, using the same start point.

3. The image at the end point of the pan.

This sort of works but there is a bump between 1/2 and another between 2/3, just a slight change in image size/position.

First question is, can one fine tune the image positions? I have tried with the crop tool but the numbers make no sense.

Second question is, can one apply Pan to the clip but have it begin after a delay and end before the clip finishes? I have tried to address the purple band below the clip that signifies Pan is applied, but can't see how to adjust it indepedent of the whole clip.

Any insight much appreciated.