Is there some shortcut, key combination or extension that allows for just clicking and dragging anywhere in an image to pan the image? I know there are keys for moving the whole window and resizing it, but I can't find one for panning an image. I'll take an extension if there is one.
Middle Mouse Button. Just hold on the image and drag.
You can also hold the left mouse button over the gold icon on the bottom right and move the mouse around to scroll the image.
This is a good pair of articles/threads to look through occasionally to remind yourself of some of the things you may not know or may have forgotten.
Common Shortcuts & Hotkeys - Fantasy Grounds Customer Portal - Confluence (atlassian.net)
Advanced Fantasy Grounds Usage - 5E Ruleset Edition
Thanks for the suggestions.