athcad key bindings are thought for people using english keyboards only. Some key bindings don't work on other layouts (example: ^ for exponentiation). Some others are only available from keyboards with numerical pads (example: Ctrl - for subscript). Finally, some are in locations that are highly unconvenient for non-english keyboards.
I would recommand to add some customizable key bindings, with a key binding editor (or, at least, the ley bindings in a text or XML file that is easily understandaable and editable), to allow every user to optimize his work with the key bindings that he needs and use, and that are convenient and relevant to his environment.