Can you add a point of sale for restaurant like cashier screen quick invoice and touch screen
Manager is an accounting software. while some users have implemented it for basic POS purposes, you would not find features and ease of use compared to a dedicated POS software.
Accounting programs are being developed to include points of sale, warehouses and human resource management services, and I was hoping programmers would develop the program to become an integrated ERP
See my other post. Although I understand your wish for Manager to meet some of your needs and wants, it would just be easier for you to choose an application that meets your purpose, no one forces you to use Manager nor can you force Manager to deal with your needs. With Manager it will always be a compromise that the Developer tries to manage, but not one single user can have all that they want.