To change the Add to Cart: to something else, using your templates and overrides you change the language file:
and set the:
to read something else ...Code:define('PRODUCTS_ORDER_QTY_TEXT','Add to Cart: ');
To change the shopping_cart display ... you would again use your templates and overrides to customize the file:
and change the parts you do not wish to see ...
To change the checkout_confirmation ... you would again use your templates and overrides to customize the file:
and change the things you do not want to see ...