Just like the left mouse button always zooms in, and the right mouse button always zooms out, it would be convenient if the middle mouse button would always pan the universe. Having to specifically press the pan button to pan is such a drag (pun intended!)
PS - thanks for the already amazingly elegant programming!
I don't have a mouse with a middle button so I'm reluctant to do this myself, but maybe one of the other devs will be tempted. Note that you can always pan using the translucent controls that appear when you move the mouse near the top left corner (or whatever corner you prefer in Prefs > View).