You will have a hard time balancing the spice levels. You can't satisfy both Indian and non-Indian demographic or you will have to have a spicy, less spicy type of each item. As an Indian, I cant stand the westernized non spicy versions of the supposedly authentic Indian foods. So I wouldn't buy them nor eat in those type of Indian restaurants. Its the same case vice versa. Non Indians may not like the spicy versions…
I would also say that food from any region of India is Indian food, and you can further specify what type of Indian food by direction (i.e. South/North) or region (i.e. Gujurati/Rajastani/Tamil).