Seems like there's nothing wrong with my keybinds.
The keybind error with Z has to do with different keyboard mappings. German keyboards are not correctly mapped (Z an Y are changed).
Another bug:
After fighting the basilisk in the Underdark, he flees. After fleeing, one of my companions (Shadowheart) has no more actions. If I teleport, she starts flying off the map back to where she was and dies through all the traps in ther map. This happened more than once.
Bug?
After preparing my whole party for a battle (hiding them in good positions), after entering combat with one character, even when it's my turn and I go to another character for it to join the combat, my turns are skipped (with the character in combat).