Regarding the z/Z for zapping/spellcasting and similar issues, a possible long-term solution might be to have a menu for creating customised control bindings, as well as have a prompt appear the first time the game is launched suggesting the user take advantage of the option.

This might also make it easier for newcomers, as they would become aware of actions like 'clean ears' and 'wipe face'.

Probably it would also be a good idea to have a prominent 'reset to default' option in the menu and messages such as e.g. "[S] is already bound to Search, are you sure you want to rebind it to Cast Spell?"