Panning with the middle mouse button

Using my Logitech G502 Gaming Mouse and Software and Photoshop Preferences I can do many things with the mouse wheel.  Setting Photoshop Preference tools section to Zoom with mouse wheel lets me zoom in on the image so it does not fit on the screen. Logitech Gaming Software lets me set the Wheel center Click to Space Bar to switch to the hand tool so I can use the left mouse button to pan with the mouse.

Also Gaming Keyboards and Keypads

You can do it easily with XMouse Button Control

You need to place feature requests on the feedback site

Adobe Photoshop Family

Do you not get on with using the Space bar to pan?  Or are you using a tablet or something that does not a readily available spacebar?  I tried using a Cintiq Companion without a keyboard years ago, and it just wasn't working for me.

One of the best best tools for panning is the spring loaded H key. When you press H and left click pan, the documet zooms back so you can see it all, with a zoom sized box overlay to show where you'll be when you relese the mouse.