In general:
Ctl: Main Window
Shift: Main Window
Alt: alternative windows

F1-F8		Help functions
F		Menu File
P		Menu Preferences
V		Menu View
H		Menu Help

Ctl S		Scanmode
Ctl C		Copymode
Ctl F		Faxmode

Ctl ENTER	Start Scan
ESC		Cancel Scan

Ctl I		Info Dialog
Ctl Q		Quit

Ctl L		Resolution List
Ctl R		Rotoate Postscript
Ctl P		Save Device Settings (Put)
Ctl G		Load Device Settings (Get)
Ctl D		Change Directory

Ctl 1		Show Tooltips
Ctl 2		Show preview
Ctl 3		Show Histogram
Ctl 3		(Show Gamma Dialog)
Ctl 4		Show Advanced Options
Ctl 5		Show Advanced Options

Ctl B		Browse Filename

Shift Fi	Printer selection in copy mode

Shift B		Bind RGB
Shift N		negative
Shift E		AutoEnhance
Shift D		Default
Shift R		Restore Settings
Shift M		Memory (store) settings
Shift S		Setup

Alt P		Start Preview Scan
Alt ESC		Cancel Preview Scan
Alt KP_+	Zoom in
Alt KP_-	Zoom out
Alt KP_*	Zoom not
Alt KP_/	Zoom undo
Alt A		Autoselect scanarea
Alt V		Select visible scanarea

Alt I		Histogram lines for intensity
Alt R		Histogram lines for red
Alt G		Histogram lines for green
Alt B		Histogram lines for blue
Alt M		Histogram lines mode (line/pixel)
Alt L		Histogram lines logarithm