My situation is:
I have very long pictures (height 1500, width 800) which I want to view in fullscreen with zoom=100% because I can't read the text any more with zoom=fit page.
I use the mouse wheel for next image/previous image and the left mouse button for "grabbing" the document and scrolling it.
This is a little bit annoying sometimes, because I have even larger pics where I have to grab and drag a lot, but it seems the best way to handle things (mouse wheel scrolling and scrolling with arrow keys is awfully slow!)
After testing RC5 I noticed that I can make scrollbars at the sides of the fullscreen when I middle-click on a pic in the browser view. This is very nice because it makes scrolling faster.
On the other hand: when I middle-click on a pic in the "normal view", there are no scrollbars. This is very irritating.

My suggestion: Make an option "show scrollbars in fullscreen" [yes/no] and make both fullscreen modes use the same behaviour. I thought Options>View>Fullscreen>"Hide play bar" would do this, but this switch seems to have no effect whatsoever.
Second suggestion:
A key for "scroll down/up one screen" (=the thing that happens when you click on a scrollbar). Something like PgUp/PgDown would be convenient because the are single keys and not a combination. Perhaps there already is something like this, but then it is not documented in the help file, I think.
3rd suggestion:
An option to increase the number of lines/pixels scrolled when using the mousewheel/the arrow keys. I tried to increase the # of lines in my mouse driver, but there is no effect.
4th suggestion:
An option for the grab&drag(picture moving with a little hand)-mode:
a) use normal mode (like it is now)
b) use virtual scrollbar mode (like it is in the Firefox extension "All-in-one-gestures", for example)
With option b) you don't "grab" the document but a virtual scrollbar-> This speeds up the mouse scrolling on large images a lot and is even better than using the normal scrollbars at the edges of the screen because you can scroll horizontally and vertically at the same time.
Perhaps there even is use for both modes at the same time (virtual scrollbar mode=left mouse button, normal mode=middle mouse button), when viewing extremely large/magnified documents...