Grab scroll is your friend
if you use wacom type stylus, search for smartscroll from marcmoini
The 'grab scroll' option allows you to add a 'hand' type effect to anything, your wacom pen will become a million times more useful!
I have the 2nd button assigned to grab, so you can swish around in finder, and even click and drag illustrtor windows whilst the type tool is active, which used to require deselecting the type, then hitting space to grab and drag around a window.
works in preview too - obviously.