Is it possible to make the app full screen without user to have ability to close it?
Short answer: yes
Long answer:
Don't do it, it is bad for user experience. I ever got uncloseable programs, I hate it ... I deleted them immediately, it's super annoying. If you play computer games, you know most of them are run in full screen mode, without title bar and the close button on the corner. Even without the close button, user still can 'force' it to close using Task Manager. But you still can make it uncloseable. If pay attention on the antivirus installed in your PC, you will notice most of them are not able to fully close even you 'end task' it on your Task Manager. I haven't tried but I believe they can achieve it by starting some additional programs (as services) and keep monitor if one of them is closed, so they will start it again on memory automatically.
And is it possible to when some text is added to field automaticly submit the form?
Yes, it is easy. Usually you put something like this below in the form's
OnCreate event:
Edit1.Text := 'the text you want to put';