Found somewhat a solution for the problem. There is this freeware program
http://www.autohotkey.com/download/ which allows you to rebind every key by using very simple scripts.
Here's how it all works (slightly edited Quick-start Tutorial):
1. Download and install AutoHotkey.
2. Right-click an empty spot on your desktop or in a folder of your choice.
3. In the menu that appears, select New -> AutoHotkey Script. (Alternatively, select New -> Text Document.)
4. Type a name for the file, ensuring that it ends in .ahk. For example: The Witcher 2.ahk
5. Right-click the file and choose Edit Script.
6. On a new blank line, type the following:
x::y
7. Save the file (no need to close it).
8. Double-click it and the program will open automatically and will activate your script.
9. From now on, when you press 'x' it will act like you pressed 'y'. Simple as that.
9. To deactivate the script you can just close the program.
Key list:
http://www.autohotkey.com/docs/KeyList.htm More practical example (my script):
q::j
e::i
~Tab::m
'Q' will now open quest / journal, 'E' — equipment / inventory, 'Tab' — map. '~' before Tab means that its native function will not be blocked, so I would be able to AltTab.
The program also supports mouse wheel rebinding but it doesn't seem to work properly in the game (works fine in Windows). Probably because 'mouse wheel hotkeys generate only down-events (never up-events)'.
Hope that helps.