See this demo project:
Thanks so much, the dragging/scrolling is perfect now!
However there is now a new issue. In my project the player stays in the center of the screen (based on the viewport), but when I pan the view back and forth, the player gets really jittery and lags behind the panning slightly.
I tried to fix this by setting a camera object on a separate "hud" layer and anchoring it to the center without parallax to have an object that is 'perfect' (no jittering), and then setting the Player to always be at the same X axis as that object, but it didn't work. I suspect you can't have objects interacting from different layers.
Is there any other way to keep my character jumping in the center of the screen, while the view pans around, without jittering?
Here is another link to the (updated) project.