Mathematical relationship between Motion parameters for two images.

It’s much easier to handle this kind of workflow in After Effects since it lets you adjust scale in both percentages and pixels. But if you’d rather stick with Premiere Pro, you can achieve a similar result by working with layers in a single graphic, like you would in Photoshop, instead of managing multiple tracks.

Here’s a simple way to do it:

1. Open your sequence in the Timeline.
2. Go to Graphics and Titles > New Layer > Rectangle to create a new layer.
3. Select the clip in the Timeline, then go to Window > Properties.
4. Drag your Photoshop layers from the Project panel into the Properties panel (and delete the rectangle shape layer).
5. In the Effect Controls panel:
   • You can adjust the position and scale of each individual layer.
   • Or use Vector Motion to adjust the position and scale of all the layers at once.
6. If needed, group multiple layers together to make changes to the entire group in one go.
   
   

If you want to dive deeper, this video is a good introduction to animating with graphic layers in Premiere Pro: Animate Stunning Graphics Using Only Premiere Pro

I will also add, that anchor points move ... bizarrely ... if you touch them after doing other movement of the image.

So if you need to move an anchor point, do it before doing anything else. If you need to then move it again, nest the clip, then move the anchor point, then do additional image movement.

But better yet is Ae for this.

As Kevin said, After Effects would be the logical place for this project.

As for moving things 'locked to the background', it would be to have those elements in a nested sequence and you can move all the tracks together.

I think this problem cannot be solved with the info I have provided. Anchor points have to be specified, both for the background and Aunt Leila, specifically the location of her foot on the ground so she stays in place. I've done it manually, but it was time consuming because there's a second person that I also want to remain in place relative to the background. And I haven't been able to do that yet.

I'll take this problem to the Physics Forum, in case I ever have to do it again. I'll be asking (with a lot more explanation than what follows):  given an image in the Program Window that has six parameters (Position X, Position Y, Scale Rotation, Anchor X, Anchor Y), and I then change the Anchor Point, what values of Position X and Position Y do I have to enter so the image in the Program Window appears unchanged?

If I receive an answer, I'll post the equation here.