What are the hotkeys for the VGA version? I found a reference card for the EGA one but some of them don't seem to work.

I've found one:
Tab or Ctrl+I=Inventory

The reference card on GOG is for QfG 5 only.

CTRL+S brings up the status screen
F5 is save
F7 is load
F9 is restart
CTRL+Q quits the game

Most of the hotkeys were ditched in favor of the mouse interface, which is a shame. But, you can have some fun with CTRL+S in the Brigand's Room before throwing the Dispel Potion. :)