Customised Firmware for Android minipc

I have developed my own android application (for Android 4.0 and up). Since the application needs to run 24h on an android device, I need to improve the system stability and performances. The typical user of the device is not supposed to use the system freely. I want to produce a customised firmware so to have total control on the system. Please, bid only if you are able to deliver all of the following 10 requirements: === 1. Adding system applications The final system should be "minimal", meaning that the only system applications should be: (i) Flash Player; (ii) my own main application; (iii) a secondary application needed by the main own. 2. Removing System applications Remove all of the non vital components, among which: (i) phone-related modules; (ii) bluetooth modules 3. Root privileges The firmware should have root privileges 4. Disk management The firmware should allow to use an external SD card 5. Bar management The navigation bar and the status bar should disappear when the application runs full screen 6. Automatic application-update The firmware should allow the device to automatic update of my own application. The application will be hosted on Google play but on a dedicated server I own 7. Orientation management I want that the user can choose if (s)he wants to use Portrait or Landscape orientation 8. Screen on/off The minipc is always connected with a screen. We want to switch this screen on and off, without using any physical switch. Therefore the firmware should allow to switch the screen on and off. 9. Proxy management The firmware should allow a basic management of proxy. 10. Validation test When using the application on different devices, mounting different firmwares, I have detected that the following items did not work properly: (i). View anchoring inside the custom layouts of my application (ii). z-roder (for views inside layout) (iii). Update of layouts and views at runtime The firmware should allow the application to run without any of these issues. === Additional details (including the application apk, and the device details) will be provided to the selected freelancer. Continuous interactions during the job is expected. I expect two elements to be delivered at the end of the job: 1. The full-final image (OS+kernel) for my specific device; 2. The final customised OS. Thank you.