I just had an idea about using the middle wheel mouse button as an alternate shortcut to zooming the document window. Sounds like it could be tons helpful for handy navigation. 
And down press (click and hold) to pan the document window. Not to forget. 
Hi Gummie,
there are a few shortcut to do this:
‘+’ --> Zoom In
‘-’ --> Zoom Out
‘0’ --> Zoom 1:1
‘Ctrl+0’ --> Zoom Half (very useful)
‘Space’ + ‘Click and Drag’ --> Pan Canvas
‘~’ + ‘Click and Drag’ --> Pan drawing within Canvas
hope this helps
cameyo