Thank you for contacting us.
1) Unfortunately the required functionality is not possible with the built-in functionality. If you need to avoid deleting of the image when you update the item, you will need to avoid updating of the concrete field. You will not accomplish this task if you are using automatic operations.
2) To achieve your goal you will need to handle this functionality all by yourself. You can review this online demo
which does not use automatic operations.
the Telerik team