I am working with WordPress more then two years now. I want to achieve a goal using WordPress. I am working on a project foodorder.(site) that is food order PHP custom project. And also can say my 1st PHP big project. But I am missing lot of love from wp here. So, is it possible to create similar project with WP love all the functionality. I need guidance. I am thinking to develop a custom theme for it.
But another main aim to discuss with gurus of my field that is it possible to fully customize wp-admin and disable all WP connection with WP themes, plugins, updates etc and also fully customized the look of wp back end.
And one thing more wp is open source, so is it will be legal to customize it's complete back end and than resell the whole product with own created theme and functionality?