[ManDay]

Is there any reason the "Fullscreen" option has been removed? Personally, I'd prefer every inch of extra reading space and don't have particular use for a bar at the bottom in most documents. Could that be added back?

As for the semantics of setting up the page, if I may make a suggestion, I'd say that the more simple it is, the better.

There should be exactly one option for Autocrop: Its level. Where 0 means no autocrop and everything above crops by a certain threshold in gray.

When autocrop is active, the document behaves exactly as if we were dealing with it's cropped version. No tricks.

A second setting determines the number of columns by which the Next and Previous buttons operate.

Then, orthogonal to that, we have zoom.

So in summary

--- Page Settings ---
Autocrop: 0-10
Number of Columns: 1-...
--- Zoom Actions ---
Zoom to Width
Zoom to Height
Zoom by Percent
...etc...
--- Tool Selection - Joystick ---
Zoom and Pan (up and down zoom, left and right pan left and right)
Pan (all directions pan)
--- Tool Selection - Pen ---
Zoom
Pan
Annotate (Pen)
Annotage (Eraser)
...etc...

< and > buttons advance forwards, respectively backwards through the document by the setting "Number of Columns".

This is a minimal set of options, allowing for maximum flexibility. Do you reckon with any usecase which is not covered by that?